pharmacokinetics, FIRST AID Q& A for NBDE PART II(Pharma)

Platelet inhibitors

Clopidogrel (Plavix); caution for elective dental care

Direct thrombin inhibitors

Dabigatran (Pradaxa);

A pediatric patient is scheduled to havemultiple restorative procedures carried out in the operating room under anesthesia. The drug chosen for anesthesia is fentanyl. Should this patient show signs of respiratory depression, what would be the appropriate reversal agent? A. Epinephrine B. Naloxone C. Flumazenil D. Clonidine E. Hydrocortisone

The correct answer is B. Naloxone is the drug of choice for the treatment of opioid overdose. Naloxone is a -opioid receptor competitive antagonist. Naloxone has a high affinity for the - opioid receptor in the central nervous system and is capable of competitively displacing opioids from the receptor. Flumazenil is used to treat benzodiazepine overdose. It reverses the effects of benzodiazepines by competitively inhibiting the GABAA receptor. Clonidine treats high blood pressure by stimulating the 2 receptors in the brain, which results in a decrease in sympathetic tone. Clonidine has also been used to ease withdrawal symptoms associated with the long-term use of substances, such as narcotics,alcohol, and nicotine, but not for acute reversal of narcotic overdose. It is mainly used to address the sympathetic nervous system response to opiate withdrawal, like hypertension and tachycardia, in the initial days of withdrawals

A 63-year-old male patient with a history of infrequent dental visits reports to your office with the complaint of swollen gums. He has a history of high blood pressure, high cholesterol, and was in the hospital 2 years ago after suffering a silent myocardial infarction. He also has a history of asthma. He is currently taking lisinopril,nifedipine, atenolol, simvastatin, and albuterol as needed. Which of the following medications is the most likely cause of his hyperplastic gingiva? A. Lisinopril B. Nifedipine C. Atenolol D. Simvastatin E. Albuterol

The correct answer is B. Nifedipine is an example of a calcium channel blocker (CCB). These drugs work by blocking calcium entry into smooth muscle cells of the heart and its associated arteries. Calcium is responsible for heart contraction and narrowing of the arteries, and its inhibition results in vasodilation of coronary and peripheral blood vessels and decreased contraction force (negative inotropic effect) and rate (negative chronotropic effect). CCBs are used for treating hypertension, angina, and arrhythmias. Side effects of CCBs include gingival hyperplasia and orthostatic hypotension. Other drugs that cause gingival hyperplasia include phenytoin and cyclosporine. Lisinopril is an example of an ACE inhibitor; is used for treating hypertension and heart failure, prevention of strokes, and kidney failure; and improves survival after heart attacks. ACE inhibitors work by inhibiting the enzyme ACE, which catalyzes the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor and stimulant of aldosterone. As a result,blood vessels dilate and sodium and water retention is reduced. In addition, ACE inhibition blocks the breakdown of bradykinin, a vasodilator. The side effects of ACE inhibitors can be remembered using the mnemonic "CAPTOPRIL" (another example of an ACE inhibitor),which stands for: cough, angioedema, potassium excess, taste changes, orthostatic hypotension,pregnancy contraindication, rash, indomethacin inhibition, liver toxicity. Gingival hyperplasia is not on this list. Atenolol is an example of a beta adrenergic receptor blocker. Beta blockers inhibit beta adrenergic substances from affecting the sympathetic nervous system. In the heart, their effect is to lower cardiac output and decrease the workload of the heart, resulting in reduced peripheral pressure. These drugs are used for hypertension,angina, arrhythmias, and migraine headaches.Side effects include orthostatic hypotension and difficulty breathing, particularly in asthmatics. Simvastatin is an example of HMG-CoA reductase inhibitors (statins) that block the ratelimiting step in cholesterol synthesis. This class of drugs is used to control hypercholesterolemia and coronary artery disease. Adverse effects of statins include muscle pain, with an increased risk of muscle toxicity (rhabdomyolysis) when these drugs are taken concomitantly with drugs that inhibit the CYP3A4 enzyme system, including erythromycin and azole antifungals. Albuterol is an example of a beta-2 adrenergic agonist, meaning that it stimulates beta-2 receptors located on the muscles surrounding the airways. Stimulation of these receptors induces bronchodilation. It is taken via inhalation to treat acute asthmatic attacks. Side effects include anxiety,tremors, fast heart rate, and throat irritation

Which one of the following is true about opioids? A. They can interact with , , and/or opioid receptor in PNS and enteric nervous system B. They can cause respiratory depression C. They can cause diarrhea D. All can cause mydriasis E. Naloxone is an example of an opioid

The correct answer is B. Opioids (e.g., morphine, heroin, codeine, and fentanyl) interact with opioid receptor in the CNS and GI. They are used to treat for pain, cough, and diarrhea.Side effects include respiratory depression, constipation,miosis, and CNS depression. Opioid use can lead to abuse and dependence. Naloxone is an opioid receptor antagonist.

What is type 1 hypersensitivity?

IgE mediated- activation of mast cells; anaphylaxis and angioedema

What is a type A adverse drug reaction?

Predictable and often dose-dependent; effect on the individual

Which one of the following benzodiazepines does not require Phase I metabolism by the liver? A. Alprazolam B. Oxazepam C. Midazolam D. Triazolam E. Diazepam

The correct answer is B. Oxazepam is a benzodiazepine that does not require phase I metabolism by the liver. Therefore, it can be useful in patients with liver failure. Phase I reactions occur via oxidation, reduction, hydrolysis cyclization, or decyclization reactions to either inactivate or activate drugs. Phase II reactions involve methylation, syphation,acetylation, and glucuronidation. The smooth endoplasmic reticulum of the liver cell in the principal location of drug metabolism. Lorazepam and temazepam are the two other benzodiazepines whose levels are not significantly affected by the liver. Alprazolam, midazolam,triazolam, and diazepam all require phase I metabolism by the liver

aldosterone antagonist

Spironolactone aldactone

Angiotensin II Receptor Blockers (ARBs)

-artan

Calcium Channel Blockers

-dipine; diltiazem/verapamil - Afib

beta blocker

-olol

Proton Pump Inhibitors

-prazole

angiotensin converting enzyme inhibitor

-prill; cough

H2 receptor antagonists

-tidine

Factor Xa inhibitors

-xaban

low volume of distribution

10mg given 1mg/l in the system

high Volume of distribution

10mg only 0.01mg/l in the system

how many half lifes are required to reach steady state

5

N-acetylcysteine is used as an antidote for overdose of which of the following medications? A. Acetaminophen B. Ibuprofen C. Celecoxib D. Indomethacin E. Naproxen

The correct answer is A. Acetaminophen is used as an analgesic and antipyretic. Its mechanism is not fully known, possibly related to inhibition of cyclooxygenases in the CNS. Hepatotoxicity is a great concern with the use of acetaminophen in context of overdosing or patients with hepatic failure. N-acetylcysteine allows an increase in supply of intracellular glutathione via elevated intracellular cysteine, thereby decreasing the formation toxic metabolites

An elderly patient presents to your office with a long list of medications that she is currently taking to treat the following conditions: history of stroke, depression, arthritis, and glaucoma. In the clinical examination, you note multiple cervical caries and severe dry mouth. Which of the following medications is the most likely cause of xerostomia in this patient? A. Amitriptyline B. Aspirin C. Pilocarpine D. Nabumetone E. Physostigmine

The correct answer is A. Amitriptyline is an example of a tricyclic antidepressant (TCA). TCAs work by inhibiting the reuptake of norepinephrine and serotonin at nerve terminals.Their application is based on the theory that abnormal levels of these neurotransmitters may relate to depression in some patients. TCAs in general have an anticholinergic effect, and therefore adverse reactions may include: xerostomia, urinary retention, constipation, increased ocular pressure, and mydriasis. Other classes of drugs associated with xerostomia include: anticholinergics,anticonvulsants, antihistamines,antihypertensives, antiparkinsonians, antipsychotics,antispasmodics, appetite suppressants,barbiturates, bronchodilators, decongestants, diuretics, hypnotics, muscle relaxants, and opioid analgesics.Aspirin is the most popular antiplatelet drugand is available over-the-counter. Doses range from 81 to 325 mg/day to prevent myocardial infarctions and occlusive strokes in high-risk people. Aspirin works by irreversibly inhibiting platelet aggregation. Because of its irreversible nature, it needs to be discontinued for 5 to 7 days to allow for normal clotting following the synthesis of new platelets. Other applications of aspirin are: (1) an analgesic for minor aches and pains,(2) an antipyretic to reduce fever, and (3) an antiinflammatory medication. Adverse effects of aspirin include GI ulcers, stomach bleeding, prolonged bleeding, tinnitus, and an increased risk of Reye syndrome (characterized by acute encephalopathy and fatty liver) in children with viral diseases. Pilocarpine is a nonselective cholinergic agonist.It has a direct effect on muscarinic acetylcholine receptors and can be applied topically. It produces rapid miosis and contraction of ciliary muscles and is used by patients with glaucoma. It also stimulates the secretion of large amounts of saliva and sweat and is used to treat xerostomia,rather than cause xerostomia. Adverse effects of pilocarpine relate to its nonselective nature and include: excessive sweating and salivation, bronchospasm and increased bronchial mucous secretion,bradycardia, hypotension, and diarrhea. Nabumetone is an example of a nonsteroidal anti-inflammatory drug (NSAID). NSAIDs work by inhibiting the enzyme cyclooxygenase, resulting in lower concentrations of prostaglandins, chemicals produced by the body that are responsible for inflammation, pain, and fever. Nabumetone may be taken once a day for long term by patients with osteoarthritis and rheumatoid arthritis. The most common side effects of nabumetone affect the GI system. To reduce the incidence of GI ulceration with chronic use of this drug, a prostaglandin analog (i.e., misoprostol)may also be prescribed. Prostaglandin analogs must be used with caution because of their potential as an abortive agent or labor inducer.Other drugs used to treat osteoarthritis include: aspirin or acetaminophen, selectiveCOX-2 inhibitors, prednisone injections, and topical capsaicin. Physostigmine is an indirect acting cholinergic agonist that exerts its effect by reversibly inhibiting cholinesterase from breaking down acetylcholine, thereby increasing the level and duration of action of acetylcholine in the neuromuscular junction. It has several clinical applications, including glaucoma, urinary retention, reversal of neuromuscular junction blockage,and myasthenia gravis. Researchers have also found some potential for its use in treating depression and Alzheimer disease. Adverse reactions include the potential to cause SLUDGE,an acronym for a cholinergic syndrome with the following characteristics: salivation, lacrimation, urination, diarrhea, GI cramping, and emesis

All of the statements below about glucocorticoids are true, except: A. They function by binding to an extracellular receptor B. They decrease the production of leukotrienes and prostaglandins C. Inhibition of phospholipase A2 is a key to their mechanism of action D. They are contraindicated in Cushing syndrome E. They are commonly used in inflammation and immunosuppression

The correct answer is A. Glucocorticoids (e.g.,prednisone, triamcinolone, dexamethasone, and hydrocortisone) are used in many different clinical situations, including inflammation, immunosuppression,Addison disease, and asthma.They function by binding to intracellular cytoplasmic receptor, phospholipase, thereby indirectly inhibiting production of leukotrienes and prostaglandins.

A 60-year-old female patient with history of hypertension was recently put on antihypertensive medications. She is now reporting recent onset of polyuria and polydipsia. The patient does not appear to have any other medical conditions. Which one of the following medication is most likely of what the patient is taking? A. Hydrochlorothiazide B. Enalapril C. Terazosin D. Methyldopa E. Diltiazem

The correct answer is A. Hydrochlorothiazide is a thiazide diuretic that can lead to increase in urination. The rest of the options are all antihypertensives that work through different mechanisms. Diltiazem is a calcium channel blocker. Enalapril is an ACE inhibitor. Methyldopa is a centrally acting alpha receptor agonist. Terazosin is a peripherally acting alpha receptor blocking agent.

A 50-year-old man complains of heartburn.Which one of the following medications will help prevent acid secretion in the stomach? A. Omeprazole B. Cimetidine C. Famotidine D. Ketoconazole E. Ranitidine

The correct answer is A. Omeprazole is an irreversible inhibitor of H+/K+ ATPase of the parietal cells used to treat peptic ulcer disease. Cimetidine, famotidine, and ranitidine are H2-receptor antagonists that block histamine induced acid secretion. Ketoconazole is an antifungal medication

Which one of the following is true regarding paroxetine? A. It specifically inhibits serotonin reuptake B. It is used to treat mania C. It can be safely taken with monoamine oxidase inhibitor (MAOI) D. GI upset is not a common side effect E. Sexual dysfunction is rarely reported

The correct answer is A. Paroxetine is a selective serotonin reuptake inhibitor that is used commonly in the management of depressive disorders. It is preferred over other antidepressants because of less severe side effects.Common side effects include GI upset, decreased libido, and sexual dysfunction. Taking SSRI in combination with MAOi can increase the risk of having life-threatening serotonin syndrome (autonomic instability, somatic, and cognitive symptoms).

drugs that cause angioedema

ACE inhibitors, anxiolytics, anti fungal agents, and cholinesterase inhibitors

Which one of the following statements is true regarding sulfonylureas? A. They include glipizide and glyburide B. They stimulate insulin release from alpha cells of pancreas and binding of insulin to target tissue and inhibit release of glucagons C. It can decrease hepatic gluconeogenesis D. It is the first-line medication for type I diabetes mellitus E. Lactic acidosis is a concern for sulfonylureas overdose

The correct answer is A. Sulfonylureas include glipizide, glyburide, tolbutamide, and chlorpropamide. They stimulate insulin release from beta cells of the pancreas and binding of insulin to target tissues. They also inhibit release of glucagon. Metformin is a biguanides that can decrease hepatic gluconeogenesis. Lactic acidosis is a concern for metformin overdose. Both types of medications are used commonly in the treatment of type II diabetes mellitus.

After 0.6 g of Drug A was administered intravenously,the plasma concentration is 100 g/L.What is the correct volume of distribution of Drug A in liters? A. 6 B. 60 C. 0.167 D. 166.67 E. 0.006

The correct answer is A. Volume of distribution (Vd) is defined as total amount of drug in the body/plasma drug concentration = 600 mg ≈ 100 mg/L = 6 L.

A patient presents to your office with the following current medication list: warfarin, aspirin,and clotrimazole. Before beginning the procedure you had planned, you decide it is worthwhile to look up further information on these drugs. Warfarin is metabolized in the liver and has a volume of distribution of approximately 0.14 L/kg. You are slightly concerned that this patient may experience increased bleeding because of these properties along with the concomitant medications he is taking. Which of the following properties of a drug is the least likely to contribute to a significant adverse interaction with another drug? A. The drug has a low therapeutic index B. The drug has minimal protein binding C. The drug undergoes extensive cytochrome P450 metabolism D. The drug is an enzyme inducer E. The drug has a low volume of distribution

The correct answer is B. A drug with minimal protein binding is least likely to contribute to a significant adverse drug interaction. On the other hand, drugs that are highly protein bound can be displaced by other drugs that are highly protein bound when taken simultaneously. For instance, warfarin is typically 99% plasma protein bound, meaning that only 1% of the drug is free and therefore only 1% is active. Drugs like aspirin or other salicylates will compete for the protein receptor sites that warfarin has a tendency to bind to. This competition will cause displacement of warfarin, resulting in greater availability of the drug and therefore an increased effect, which in warfarin's case can result in increased bleeding. Therapeutic index (TI) represents the margin of safety of a drug. Drugs with a low (or narrow) TI have a small margin of safety. TI is equivalent to LD50/ED50, or the lethal dose in 50% of patients compared with the effective dose in 50% of patients. If a drug has a low TI, such as a TI of 3, this means that if only three times as much as the effective dose is taken, there is a 50% chance for a lethal effect.Drugs that are metabolized by the CYP450 enzyme system in the liver are subject to changes in metabolism when taken concomitantly with other drugs that modify the activity of the CYP450 system. Many drugs may increase or decrease the activity of CYP450 by acting as an inducer or inhibitor, respectively, and resulting in depletion or accumulation of the drug in question, respectively. Drugs that are enzyme inducers, as in those associated with the CYP450 system, have the potential to speed up metabolism of a drug, thereby depleting the presence of the drug. The volume of distribution is used to describe the quantity of medication in the plasma and the rest of the body. Drugs with a low volume of distribution have a higher concentration in the plasma and the potential for greater activity.

Which of the following local anesthetics is most likely to cause an allergic reaction? A. Lidocaine B. Propoxycaine C. Prilocaine D. Mepivicaine E. Bupivacaine

The correct answer is B. Allergic reactions to local anesthetics typically involve the ester anesthetics.The sensitivity is usually because of a reaction against the preservative found in ester local anesthetics called para-aminobenzoic acid (PABA). Among the answer choices, only propoxycaine is an ester anesthetic. The others are amide local anesthetics

The plasma concentration of drug X is 150 mg/L,and it is eliminated from the body at a rate of 3 mg/min. Which of the following is the clearance rate of drug X? A. 0.2 L/min B. 0.02 L/min C. 2 L/min D. 50 L/min E. 200 L/min

The correct answer is B. Clearance is defined as rate of elimination/plasma drug concentration = 3 mg/min/150 mg/L = 0.02 L/min.

An emergency patient presents to your office with trismus, fever, and a swelling on one side of his lower face. The patient questionnaire he filled out in the waiting room states that he has no medical issues, takes no medications, and has a history of alcohol abuse but has been sober for one month. During the examination, you observe extensive decay on #18 and a small abscess in the apical region of #18. The tooth is hopeless, but before extraction, you decide to place the patient on an antibiotic to clear up the acute intraoral infection. Which of the following antibiotics would you want to avoid because of the patient's social history and the potential disulfiram-like effect? A. Clarithromycin B. Metronidazole C. Clindamycin D. Doxycycline E. Rifampin

The correct answer is B. Disulfiram is used in the treatment of chronic alcoholism by causing an acute sensitivity to alcohol. The underlying mechanism is the accumulation of acetaldehyde in the blood because of inhibition of hepatic aldehyde dehydrogenase by disulfiram. Acetaldehyde is one of the major causes of the symptoms of a "hangover." Within minutes of its accumulation, the individual can become acutely ill with a severe "hangover," experiencing generalized flushing, nausea, vomiting, headache, and more serious symptoms, such as accelerated heart rate and circulatory collapse. There are several other drugs that can produce this disulfiram-like effect including: phenacetin, antibiotics, such as nitrofurantoin, cephalosporins, and metronidazole, anti-angina medication (nitrates), and first-generation sulfonylureas,such as chlorpropamide and tolbutamide. Metronidazole works by inhibiting DNA bacterial synthesis, exclusively against strict anaerobic infections. Clarithromycin is in the class of macrolide antibiotics that exert their effects by inhibiting bacterial protein synthesis. Clarithromycin should be prescribed with caution to patients taking other drugs that interact with the CYP3A4 enzyme, found largely in the liver. Because clarithromycin is a CYP3A4 substrate, it may cause increased serum levels of other drugs that are CYP3A4 substrates, including several benzodiazepines, calcium channel blockers, immunosuppressants, statins, SSRIs, TCAs, azole antifungals, and others such as mirtazapine, nefazodone, venlafaxine, terfenadine, cisapride, theophylline, and warfarin. It is also possible for other drugs, CYP3A4 inhibitors and CYP3A4 inducers, to cause increased or decreased levels of clarithromycin, resulting in adverse reactions or ineffectiveness, respectively. Clindamycin is an antibiotic that works by inhibiting bacterial protein synthesis. The most severe common adverse effect of clindamycin is Clostridium difficile-associated diarrhea (the most frequent cause of pseudomembranous colitis,a potentially lethal condition). This side effect can occur with other antibiotics as well but most commonly occurs with clindamycin use. Because clindamycin concentrates in bone, it is often used in dentistry to treat periapical bony infections. Doxycycline is a member of the tetracycline class of antibiotics, another group of antibiotics that works by inhibition of bacterial protein synthesis. Significant adverse effects of doxycycline include photosensitivity and discoloration of teeth and inhibition of bone growth when taken during development in infants and children. Rifampin is antituberculosis drug. The most serious adverse effect of rifampin is related to its hepatotoxicity

Many people use herbal supplements as alternate therapy for a variety of conditions. It is important for physicians and dentists to know what medications their patients are taking, including herbal supplements. St. John'sWort is an example of a supplement commonly used to relieve depression. The simultaneous ingestion of the herbal St. John's Wort has been shown to decrease the half-life of oral contraceptives because St. John's Wort: A. Blocks the active secretion of oral contraceptive B. Induces CYP-3A4 in the gut and liver C. Increases stomach acidity D. Blocks both estrogen and progesterone receptors E. Decreases serotonin levels in the brain

The correct answer is B. St. John's Wort is a CYP3A4 inducer. As an inducer, St. John'sWort causes the CYP3A4 enzyme (part of the CYP450 enzyme system) to become more active. Drugs that are substrates of CYP3A4 are therefore metabolized more rapidly, and their blood levels are reduced. In the case of oral contraceptives, if inadequate amounts of hormone are present,the overall effectiveness of the oral contraceptive may be reduced. Patients taking St. John's Wort may require increased dosages of other drugs.Other examples of CYP3A4 substrates include calcium channel blockers, cyclosporine, benzodiazepines,azole antifungals, erythromycin and clarithromycin, antiretrovirals, statins, and SSRIs. St. John'sWort does not block active secretionof the oral contraceptive, does not affect stomach acidity, does not block estrogen and progesterone receptors, and does not decrease serotonin levels in the brain. The exact mechanism by which St. John's Wort functions to decrease depression is unclear. However, it is believed that one way the herbal product is thought to exert its effect is by inhibiting the reuptake of serotonin, thereby increasing levels of serotonin in the brain

Which one of the following is true regarding tricyclic antidepressants (TCAs)? A. They include phenelzine, isocarboxazid, and tranylcypromine B. They inhibit reuptake of norepinephrine and serotonin into presynaptic nerve terminals C. They are only used in depression D. Arrhythmias are a concern with TCA overdose E. Orthostatic hypotension rarely occurs

The correct answer is B. TCAs (e.g., amitriptyline,imipramine, nortriptyline, desipramine, trimipramine, doxepin, and clomipramine) can inhibit reuptake of norepinephrine and serotonin into presynaptic nerve terminals. Besides usage in depression, TCAs can be used in the treatment of neuropathy and panic disorders. Its side effects include antimuscarinic, antiadrenergic,and antihistamine effects such as dry mouth,orthostatic hypotension, and sedation. Serious adverse effects include coma, convulsion, and cardiotoxicity (arrhythmias).

You received a call from the emergency department at your local hospital concerning a pediatric patient that you recently treated. The patient is a 6-year-old boy who was brought to the emergency department in a comatose state. His parents state that he recently visited your office for extraction of a grossly decayed primary tooth. The parents state that they had given him a few pain pills to help with the discomfort following the extraction. Physical examination of the boy revealed "comatose, hepatomegaly, and yellow sclera." A computerized tomography (CT) scan revealed cerebral edema. Laboratory results showed elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and prothrombin time (PT). The emergency department physician believes that treatment with the antidote N-acetylcysteine is necessary but has called you to confirm whether you prescribed any medications. What agent is most likely involved in the symptoms of this patient? A. Aspirin B. Acetaminophen C. Codeine D. Celecoxib E. Ibuprofen

The correct answer is B. The most likely cause of these symptoms is an overdose of acetaminophen (APAP). APAP is used as an analgesic and antipyretic. Its exact mechanism is unknown. APAP is metabolized in the liver by CYP2E1 to N-acetyl-benzoquinoneimine (NAPQI), a toxic by-product, which is later inactivated by glutathione. In the case of an overdose, glutathione stores are depleted andNAPQI damages hepatocytes. Signs of liver toxicity include hepatomegaly, jaundice, GI bleeding, and encephalopathy. Death may occur because of cerebral edema, sepsis, or multiorgan failure. Treatment may include the ingestion of activated charcoal or the antidote, N-acetylcysteine. These are best given within 12 hours before the liver damage becomes irreversible. If treatment is not initiated quickly enough, liver failure may ensue requiring a liver transplant. It is important for parents to pay close attention to the dosages of medications that they provide to their children.For children younger than 12 years and/or less than 50 kg in weight, the maximum daily dosage of acetaminophen is 80 mg/kg (not to exceed a cumulative daily dose of 2.6 g). Weight-based oral dosing for children is 10 to 15 mg/kg every 4 to 6 hours with a maximum of five doses per 24-hour period. Aspirin is an irreversible inhibitor of COX-1. It serves as an analgesic, antipyretic and, antiinflammatory agent and inhibits platelet aggregation. Adverse effects of aspirin include: GI irritation,tinnitus, vertigo, hypersensitivity, and bleeding complications. An additional adverse effect that many parents may not be aware of is its ability to serve as a trigger for Reye syndrome,a highly lethal disease. To avoid Reye syndrome,aspirin (and its derivatives) should not be given to children with chicken pox or influenza B infection. Reye syndrome may be misdiagnosed as a drug overdose and blood work would be helpful to confirm the diagnosis. The treatment for Reye syndrome should include: hypertonic IV glucose solutions and mechanical ventilation.Codeine is an example of a narcotic used as an analgesic agent and sometimes for its antitussive and antidiarrheal properties. Narcotics are centrally acting drugs that work by binding to opiate receptors (opiate agonist). In the case of codeine, which is a prodrug, its active metabolites, including morphine, bind to the opiate receptors. Codeine is converted to morphine via the CYP2D6 enzyme, and because of its interaction with the CYP450 enzyme system, its serum levels are susceptible to changes by interactions with other drugs (i.e., CYP2d6 inducers). A potentially serious side effect of codeine toxicity is respiratory depression, and in the case of a codeine overdose, the reversal agent,naloxone, should be given. Codeine, like other narcotics, can cause a physical or psychological dependence as well as tolerance to the drug to develop. Celecoxib is a variation of an NSAID and is classified as a selective COX-2 inhibitor. It is used in patients with gastric ulcers when the inhibition of COX-1 should be avoided. It has similar anti-inflammatory effects as traditional NSAIDs. According to some research, when celecoxib is used for long term, it is capable of producing cardiotoxicity. Ibuprofen is a traditional NSAID that works by non selectively inhibiting COX-1 and COX-2. Ibuprofen has analgesic, antipyretic, and antiinflammatory effects. The major concern with the overuse of ibuprofen is the increased risk of GI ulcerations and GI bleeding and nephrotoxicity.

Your patient presents to your office and reports that he recently completed a 2-month course of the following medications: isoniazid, rifampin,ethambutol, and pyrazinamide. He states that a few months back, he acquired an infection while working at a homeless shelter in the nearby city and was admitted to the hospital after developing pneumonia. His most recent chest x-ray was negative, but he still has a positive skin test. On the basis of the disease, this patient has been treated for and the intraoral image taken during the examination, what oral mucosal lesion does this patient have? A. Linea alba B. Nonhealing ulcer C. Perioral vesicles D. Hairy leukoplakia E. Lichen planus

The correct answer is B. The patient described above was taking antitubercular medications to treat tuberculosis (TB), a bacterial infection caused by Mycobacterium tuberculosis. It is caused by inhalation of the bacteria and can easily be spread in crowded areas such as homeless shelters. The medications listed above are typically given together for 2 months in the case of active infection, and after 2 months, only two drugs are continued. Active infection is determined by a positive skin test, an abnormal chest x-ray, and sputum containing TB bacteria.Treatment can continue for months or years depending on the patient. If a patient has TB in an inactive state, an antibiotic, typically isoniazid, may be given alone. Rifampin is metabolized largely in the liver by the CYP450 enzyme system, and it is, therefore, important to be aware of the effect it can have on the metabolism of other drugs metabolized by CYP450 enzymes, including oral contraceptives, warfarin, and azole antifungals. One of the oral signs of TB is a chronic nonhealing ulcer, most commonly on the dorsum of the tongue, which occurs following lung infection. The differential diagnosis of a tuberculosis ulcer should also include: aphthous ulcers, traumatic ulcers, syphilitic ulcers, and malignancy. The diagnosis can be confirmed by the presence of acid-fast bacilli in the specimen. Linea alba is an example of a mucosal lesion caused by trauma, typically cheek biting. It appears as a raised white line in the buccal mucosa, usually along the plane of occlusion. Under a microscope, it appears as hyperkeratosis. It is a variation of normal and therefore requires no pharmacologic treatment. Perioral vesicles are associated with the herpes simplex virus. Primary infection is predominant among children. The virus cannot be cured with medications and remains latent in the trigeminal ganglion. Pharmacologic treatment for herpes virus is aimed at treating the symptoms. Topical agents to treat the vesicles include 1% penciclovir cream. In addition, antiviral medications, such as acyclovir (mechanism: inhibits viral DNAsynthesis), valacyclovir, and famciclovir, can be effective when given systemically and when initiated early; however, the symptoms usually resolve on their own in 10 to14 days. Hairy leukoplakia is associated with the Epstein-Barr virus and occurs mostly in people infected with HIV. Hairy leukoplakia is an opportunistic infection that presents as a nonpainful white plaque along the lateral borders of the tongue. Hairy leukoplakia does not always require treatment. When it is treated, the following medications may be used: systemic antivirals(to slow down EBV), and topical agents such as podophyllum resin solution and tretinoin (retinoic acid).Lichen planus is thought to be caused by cytotoxic cell-mediated hypersensitivity and is sometimes associated with hepatitis C. Lichen planus appears as a white, lacy rash (Wickham's striae)on the buccal mucosa. Certain drugs, such as those containing arsenic, bismuth, or gold, can cause a response in the oral mucosa that is indistinguishable from lichen planus. In addition, long-term use of antimalaria drugs, such as quinidine, may produce lichen planus. No treatment is required for asymptomatic lesions. If symptomatic (itchiness, unpleasant appearance), topical steroid creams, antihistamines, or systemic steroids can be used. If the question above described a patient with hepatitis C, he may have been taking the following antiviral medications: interferon (peginterferon) or ribavirin.

Which one of the following statements is true regarding heparin? A. Its effect cannot be reversed with protamine sulfate B. It can bind and activate antithrombin III, resulting in the inactivating thrombin and factor Xa C. It can lead to decrease in PTT, which is a clinical measure used to follow the anticoagulant effect caused by heparin D. It decreases the synthesis of vitamin K coagulation factors E. There are no applications of heparin in pulmonary embolism

The correct answer is B: Heparin can bind and activate antithrombin III, resulting in the inactivating thrombin and factor Xa. This leads to increase in PTT, a marker for the heparin's anticoagulant effect. It is not related to synthesis of vitamin K coagulation factors, unlike warfarin. Clinical applications of heparin include pulmonary embolism, ischemic myocardial infarction, and deep venous thrombosis. Overdose of heparin can be reversed with protamine sulfate

Which of the following is correct regarding side effects of angiotensin-converting enzyme (ACE) inhibitors? A. Hypertension B. Hyperkalemia C. Cough D. Cerebral edema E. Depression

The correct answer is C. ACE inhibitors, such as captopril, enalapril, and lisinopril, block angiotensin-converting enzyme, resulting in the decrease in conversion of angiotensin I into angiotensin II, hence a potent vasoconstrictor. Adverse effects of ACE inhibitors include cough,angioedema, proteinuria, hyperkalemia, taste changes, orthostatic hypotension, fetal toxicity, and rash

One of your friends, who is also a patient, is in your office for a routine visit. While in your office,she asks if you can write a prescription for one of the drugs her primary care physician normally prescribes for an existing condition. Your friend, the patient, says she does not have much time to make an appointment with her primary care physician so she would really appreciate if you could write a script for the pharmacist. When faced with this question, as a practicing dentist, it is important to keep in mind that you can legally write prescriptions for which of the following drugs? A. Oral contraceptives B. Blood pressure lowering drugs C. Analgesic agents D. Antidiabetic agents E. Amphetamines F. Antiasthmatics

The correct answer is C. Analgesic agents, such as narcotics, are commonly prescribed by dentists to treat emergencies and preoperative and postoperative pain. Dentists may prescribe medications and controlled substances only for dental-related conditions. The ADA defines dentistry as follows: ". . . the evaluation, diagnosis, prevention and/or treatment (nonsurgical, surgical or related procedures) of diseases, disorders and/or conditions of the oral cavity, maxillofacial area and/or the adjacent and associated structures and their impact on the human body; provided by a dentist, within the scope of his/her education, training and experience, in accordance with the ethics of the profession and applicable law." Any medication that falls within the scope of this definition can be prescribed by a dentist. Under no circumstances may a dentist prescribe anything outside the course of his/her practice of dentistry. To do so is a serious violation of the laws and regulations, and a dentist may be disciplined by the Board. A dentist must avoid self-prescribing, and any medications prescribed for office staff or family members must be solely for dental-related conditions and must be clearly and specifically documented in the patient's file. Oral contraceptives, antihypertensives, antidiabetic agents, amphetamines, and antiasthmatics do not fall within the scope of dentistry and therefore should not be prescribed by a dental practitioner

A 15-year-old male patient presents to your office for an initial dental visit. While reviewing the patient's medical history with him and his parents,he reveals that during a recent basketball game he suffered from chest pain and fainted. After several tests, including an echocardiogram, he was diagnosed with hypertrophic cardiomyopathy. He also has a history of exercise-induced asthma. He has an albuterol inhaler but cannot remember the name of the medication he was recently put on for his heart condition. Which of the following beta-blockers is he most likely taking? A. Propranolol B. Labetalol C. Metoprolol D. Nadolol E. Timolol

The correct answer is C. Beta-blockers inhibit endogenous catecholamines (i.e., epinephrine) from stimulating beta adrenergic receptors, part of the sympathetic nervous system. There are two types of beta receptors, beta-1 and beta-2, located mainly in the heart and the lungs, respectively.When beta-1 receptors are blocked, the result is reduced cardiac output and decreased workload of the heart because of negative chronotropic and inotropic effects. When beta-2 receptors are blocked, the result is bronchoconstriction. On the basis of the cardiac effects, beta blockers are indicated for the treatment of hypertrophic cardiomyopathy, a condition in which the cardiacmuscle is hypertrophic without any obvious cause. All of the answer choices are examples of beta blockers; however, because this patient also has asthma, it would be advisable to use a cardioselective beta blocker, specific for beta-1,which will not cause the unwanted side effect of bronchospasm, sometimes observed when nonselective beta blockers are taken. The only example above of a cardioselective beta blocker is metoprolol. Propranolol is a nonselective beta blocker,also referred to as a beta-adrenergic blocking agent, beta-adrenergic antagonist, or a beta antagonist. In general, beta blockers are used for hypertension, cardiac arrhythmias, chest pain (angina), migraine headaches, and glaucoma. Labetalol is amixed alpha-1 and beta blocker.By also blocking alpha-1, there is an additional vasodilation effect. Because of the additional alpha-1 blockade, it is important to be aware of the risk of orthostatic hypotension when the patient leaves the dental chair. Labetalol is used to treat hypertension and is specifically indicated to treat pregnancy-induced hypertension. Pregnancy-induced hypertension (HTN) is often associated with pre-eclampsia, a condition in which there is increased protein in the urine(proteinuria). Nadolol and timolol are nonselective beta blockers.

All of the following statements are true regarding bioavailability, except: A. Route of administration is important in determining bioavailability B. High hepatic first pass effect decreases bioavailability C. Degradation of drug prior to absorption increases bioavailability D. Hydrophilic drugs are less able to cross lipid-rich cell membranes than hydrophobic drugs E. IV administration yields 100% bioavailability

The correct answer is C. Degradation of drug prior to absorption decreases bioavailability. Bioavailability is a measure of how much drug reaches the circulatory system and is available at the site of action. Factors influencing the bioavailability of a drug include: route of administration(IV>oral), degradation of drug prior to absorption (decreases bioavailability), efficient gastrointestinal absorption (increases bioavailability),drug solubility (hydrophobic better absorbed than hydrophilic), hepatic first pass effect (decreases bioavailability), and drug chemistry

All of the following statement is true regarding NSAIDs, except: A. Aspirin irreversibly inhibits cox-1 and cox-2 cyclooxygenases B. All NSAIDs, except aspirin, are reversible inhibitors of cox-1 and cox-2 cyclooxygenases C. Prostaglandin synthesis is rarely affected D. They are used for inflammation, analgesia,and antipyrexia E. Side effects include dyspepsia, GI ulcers, and renal failure

The correct answer is C. Nonselective NSAIDs are commonly used for inflammation, analgesia,and antipyrexia. They can inhibit both cox-1 and cox-2 cyclooxygenases (aspirin irreversibly,others reversibly). This can lead to a decrease in prostaglandin synthesis. Common side effects include dyspepsia, GI ulcers, and renal failure.Aspirin is also associated with Reye syndrome

Which drug is most appropriate to treat oral candidiasis? A. Penicillin B. Amphotericin B C. Nystatin D. Tetracycline E. Valacyclovir

The correct answer is C. Nystatin is a polyene antifungal effective against molds and yeasts including the Candida spp. The drug has minimalmucosal absorption and is thus used as a topical treatment for oral candida. The other answer choices are ineffective against yeast organisms .Amphotericin B is also a polyene antifungal but is used intravenously to treat systemic fungal infections

A patient presents to your office with complaints of a burning tongue. She is overweight and says her average fasting blood glucose level is 326 mg/dL. She also states that her most recent HbA1c was 9%. The patient was prescribed several medications by her physician but claims that most of them she does not take because she forgets.Which of the following medications should the patient be taking? A. Levothyroxine B. Hydrocortisone C. Insulin D. Omeprazole E. Ranitidine

The correct answer is C. On the basis of the symptoms described and the laboratory values provided, this patient is suffering from diabetes and malnutrition. The patient is not taking the appropriate medications to treat these conditions and therefore has higher than normal HbA1c and glucose values. The best answer choice would therefore be insulin. Insulin is taken subcutaneously by patients type I diabetes who lack endogenous insulin. Other antidiabetic drugs that are effective only in patients with type II diabetes include: sulfonylureas (increases insulin release), biguanides, such as metformin and glita zones (increase sensitivity to insulin),and alpha-glucosidase inhibitors (slow digestion of starch).

Which one of the following beta-lactam antibiotics has antipseudomonal properties? A. Penicillin V B. Penicillin G C. Piperacillin D. Amoxicillin E. Ampicillin

The correct answer is C. Piperacillin along with carbenicillin and ticarcillin are beta-lactamase resistant antibiotics. They have extended spectrum against many Gram-negative bacilli, including Pseudomonas aeruginosa. The remaining antibiotics are all penicillin or its derivatives that do not have antipseudomonal effects.

What do prazosin, doxazosin, and terazosin have in common? A. They are all alpha-2 receptor blocker that causes a decrease in peripheral vascular resistance B. They are diuretics used to control hypertension C. Side effects of the drugs include orthostatic hypotension D. They are noncompetitive alpha-receptor blockers. E. They rarely cause headache or dizziness

The correct answer is C. Prazosin, doxazosin,and terazosin are competitive alpha-1 receptor antagonists that are used to lower peripheral vascular resistance. They can be used to control hypertension and urinary retention. Side effects of these medications commonly include postural hypotension, headache, and dizziness

A 75-year-old smoker with history of chronic obstructive disease presents to clinic with blood pressure of 160/96 mm Hg. Which one of the following medications is contraindicated in this patient? A. Atenolol B. Metoprolol C. Propranolol D. Esmolol E. Acebutolol

The correct answer is C. Propranolol is a nonselective beta blocker that is contraindicated in patients with COPD or asthma. It can cause bronchoconstriction by blocking the beta 2 receptors. Acebutolol, atenolol, esmolol, metoprolol, and betaxolol are all beta 1 selective blockers that are safer to use for this patient

In rats, a new anticonvulsant drug has an lethal dose (LD)1 of 20 mg, and LD50 of 30 mg, an effective dose (ED)50 of 5 mg, and an ED99 of 10 mg. What is the experimental drug's therapeutic index and safety index, respectively? A. 2 and 1.5 B. 1.5 and 2 C. 6 and 2 D. 2 and 6 E. 3 and 4 F. 4 and 3

The correct answer is C. The therapeutic index (TI) is defined as a number, LD50/ED50, the ratio comparing the lethal dose of a drug for 50% of the population to the effective dose of a drug for 50% of the population. A drug with a high (or broad) index can typically be given with greater safety than one with a low (or narrow) index. Digoxin, for example, has a very low TI and requires close monitoring of the patient's blood levels to minimize the occurrence of adverse reactions. The therapeutic index is usually calculated from data obtained from experiments with animals. The comparison of the LD50 and ED50 is most significant when the dose-effect curves from which these median doses are inferred are parallel (see graph below). The therapeutic index can also be calculated using data that does not include lethal effects and instead applies the median dose causing minimally toxic effects (TD50). The safety index is defined as a number, LD1/ED99, the ratio comparing the lethal dose of a drug in 1% of the population to the effective dose in 99% of the population. The safety index indicates by what percentage of itself a dose must be exceeded to produce a lethal effect in just 1% of the population. Clinically,the safety index is more practical than the therapeutic index, and unlike the therapeutic index, the determination of the safety index does not depend on the parallelism of the dose-effect curves from which the LD1 and ED99 are inferred. On the basis of the following calculations, choice C is correct. TI = LD50/ED50 = 30 mg/5 mg = 6.Safety index = LD1/ED99 = 20 mg/10 mg = 2.In answer choice A, these values were determined by calculating the ED99/ED50 and LD50/LD1, of which neither are the correct formulas for therapeutic index and safety index.In answer choice B, these values are the reverse of those in choice A and again, neither of the formulas used are representative of therapeutic index and safety index.Answer choice D is incorrect because the values are determined by reversing the formulas for therapeutic index and safety margin.In choice E, these values were determined by calculating LD50/ED99 andLD1/ED50, of which neither are the correct formulas for therapeutic index and safety index.Answer choice F is the reverse of those in choice E and again, neither of the formulas used are representative of therapeutic index or safety index.

Which one of the following is true about H1 antihistamines? A. They include cimetidine and diphenhydramine B. They are rarely used for allergy C. Some are more sedating than others D. loratadine is a first-generation H1 antihistamine E. They can be used for motion sickness

The correct answer is C. There are two generations of H1 antihistamine (first generation: diphenhydramine, dimenhydrinate; second generation: fexofenadine, loratadine). They are commonly used for allergies. Second-generation medications are less sedating than the ones from the first-generation. Toxicities include anticholinergic and antiadrenergic effects.

Which one of the following statements is true regarding warfarin? A. Follow PTT in determining its clinical effect B. It inhibits the synthesis of vitamin K dependent clotting factors (III, VIII, XI, XII) C. It is teratogenic D. Protein C and S levels are not affected E. It is false that warfarin is found in rat poison

The correct answer is C. Warfarin has been used as a rat poison. However, it also has clinical application in humans for long-term anti coagulation. It acts by inhibiting the synthesis of vitamin K-dependent clotting factors (II, VII, IX, X), as well as proteins C and S. This affects the extrinsic coagulation pathway; thereby, one can follow the PT or INR levels for its clinical effect. Warfarin is known to be teratogenic; therefore, a pregnancy test should be performed on patients with childbearing potential. Vitamin K is used as a treatment for warfarin overdose.

A 52-year-old overweight male patient presents to your office with erosion of the lingual surfaces of all his maxillary teeth. The patient also says he suffers from heartburn, dysphagia, and a chronic cough. The patient's physician has prescribed him cimetidine and told him to take over-the counter antacids. Which of the following is the most likely mechanism of the therapeutic effect of cimetidine? A. Eradicates Helicobacter pylori B. Neutralizes stomach acid C. Reduces GI motility and acid secretion D. Blocks histamine-2 receptors on parietal cells E. Blocks proton pumps on parietal cells

The correct answer is D. Based on the signs and symptoms that the patient described above is experiencing, he is most likely suffering from a gastrointestinal (GI) problem. All of the answer choices are mechanisms of drugs that are used to treat GI upset (i.e., duodenal ulcers, gastroesophageal reflux disease (GERD), or Zollinger- Ellison syndrome) and choice D best describes the mechanism of cimetidine, an antihistamine H2 blocker.H2 receptor blockers complete with histamine only in the GI tract and consequently interrupt the signal for the parietal cell to secrete acid, resulting in overall decreased acid secretion.When a patient is on cimetidine, it is also important to be aware of potential drug interactions that may occur because it is a CYP3A4 inhibitor and can increase levels of drugs metabolized in the liver by the CYP3A4 enzyme. Other H2 blockers (i.e., ranitidine, famotidine) are not associated with these potential interactions. Helicobacter pylori is a bacterium that is associated with gastritis, duodenal or stomach ulcers(especially recurrent ulcers), and stomach cancer, including MALT lymphoma. Infection with this bacterium is most likely acquired from contaminated food or water andmust be treated with antibiotics. Because H. pylori is capable of developing resistance to commonly used antibiotics,usually two or more antibiotics are prescribed along with a proton pump inhibitor (PPI) and/or bismuth-containing compound to eradicate this bacterium. Antacids are used to treat GI upset associated with heartburn (dyspepsia) and acid indigestion.Antacids work by neutralizing excess stomach acid (increasing pH). Antacids work relatively quickly and are meant for short-term relief. The differences in how fast antacids work and for how long they provide relief depends on what ingredients (aluminum, calcium, magnesium, sodium bicarbonate) they contain. Antimuscarinic drugs (i.e., atropine) are responsible for decreased gastric secretions and decreased GI motility. Because of these effects, in addition to being used to treat heartburn and acid indigestion, they may also be used to treat diarrhea,to prevent secretions (gastric and salivary) preoperatively, and to prevent/reduce motion sickness.Proton pump inhibitors (i.e., omeprazole) are also used to treat acid-related GI conditions and work by blocking the H+/K+ ATPase pumps on parietal cells that are directly responsible for secreting H+ ions into the stomach. By targeting the terminal step in acid secretion, PPIs are more potent than H2 blockers at reducing acid secretion

During a routine medical history interview, your patient tells you he is taking celecoxib for osteoarthritis.He has been on this medication for the past year. Compared to traditional nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, celecoxib: A. Is a more effective analgesic for acute postsurgical pain B. Produces greater anti-inflammatory responses in osteoarthritis patients C. Produces less water and sodium retention D. Produces less gastrointestinal ulcers and bleeds with chronic use E. Is more effective at fever reduction

The correct answer is D. Celecoxib is an example of a selective COX-2 inhibitor. This class of drugs works by blocking the facultative COX-2 isoenzyme but sparing the constitutive COX-1 isoenzyme. Both cyclooxygenase enzymes are responsible for the conversion of arachidonic acid to prostaglandins. The main distinction is that prostaglandins whose production requires the COX-1 isoenzyme are responsible for protection of the gastric mucosa,whereas the prostaglandins whose synthesis involves COX-2 are responsible for inflammation and pain. Traditional NSAIDs work by inhibiting both COX-1 and COX-2, thereby decreasing inflammation and pain and decreasing cytoprotection of the GI tract. Selective COX-2 inhibitors work only to decrease inflammation and pain. Chronic use of traditional NSAIDs (6-12 months) in the treatment of osteoarthritis and rheumatoid arthritis is associated with approximately 1% to 3% yearly incidence of clinically significant GI ulcers. With chronic dosing, celecoxib reduces the incidence of GI perforations, ulcerations, and bleeds by approximately 50% to 60% compared with conventional NSAIDs. An area of concern when taking selective COX-2 inhibitors is the implication that COX-1 is working unopposed, which means it is continually contributing to the synthesis of thromboxane, involved in platelet aggregation, thereby increasing the risk of thrombotic events. Traditional NSAIDs and celecoxib are equally effective as analgesics for acute postsurgical pain than celecoxib since both drugs inhibit the desired target—COX-2 prostaglandins. Some sources states that traditional NSAIDs are actually more effective and are comparable to narcotics as an analgesic without the CNS mediated side effects. Traditional NSAIDs and celecoxib also produce equal anti-inflammatory responses in osteoarthritis patients, although celecoxib may be preferred because of the tendency for osteoarthritis patients to use these drugs for long term. Traditional NSAIDs and celecoxib have similar effects on renal function as measured by glomerular filtration rate, creatinine clearance, and urinary and serum sodium and potassium values. Selective COX-2 inhibition may transiently increase sodium retention. Traditional NSAIDs and celecoxib have similar antipyretic qualities

A patient presents to your office for a surgical extraction. Following the procedure, you prescribe the patient tylenol #3 (acetaminophen + codeine). The patient is taking several other drugs concurrently. Which of the following drugs is most likely to inhibit the effectiveness of codeine? A. Terazosin B. Glipizide C. Lisinopril D. Fluoxetine E. Lithium

The correct answer is D. Codeine is a narcotic with analgesic, antidiarrheal, and antitussive properties. It is classified as a Schedule III drug and has the potential for drug abuse and dependence. Codeine is readily absorbed from the GI tract, is not bound to plasma proteins,is eliminated primarily through the kidneys, reaches its peak analgesic effect within 2 hours,and persists between 4 and 6 hours. Codeine is considered a prodrug. In the liver, codeine is converted to the active compounds morphine and codeine-6-glucuronide, which exert their effects by binding to opiate receptors. This reaction is catalyzed by the cytochrome P450 enzyme, CYP2D6. Drugs that inhibit CYP2D6 prevent this conversion to active compounds from occurring, thereby reducing the overall effectiveness of codeine. Examples of strong CYP2D6 inhibitors include selective-serotonin reuptake inhibitors (SSRIs), such as fluoxetine (choice D) and paroxetine, other antidepressants, such as bupropion, terbinafine, and quinidine. Terazosin is an alpha-adrenergic blocker. By blocking the alpha-1 receptor, terazosin causes vasodilation, thereby lowering blood pressure,and smooth muscle relaxation, particularly in the prostate. Terazosin is indicated for hypertension and benign prostate hyperplasia. The most important drug interactions to be aware of in a patient taking terazosin is if the patient is taking additional antihypertensives or vasodilators as this will increase risk of hypotension and orthostatic hypotension. Terazosin has no effect on codeine. Glipizide belongs to the class of sulfonylurea drugs used by patients with type II diabetes. Sulfonylureas work by increasing the amount of insulin release from beta cells of the islets of Langerhans of the pancreas. These drugs are ineffective if there is no insulin available, as in type I diabetes. Some sulfonylureas are metabolized by the CYP450 enzyme system in the liver, and their metabolism, like codeine, can be influenced by inducers and inhibitors of this system. Some sulfonylureas are bound to plasma proteins and can be displaced by other drugs,resulting in increased free blood levels of sulfonylureas. Glipizide has no effect on codeine. Lisinopril inhibits angiotensin-converting enzyme (ACE) that catalyzes the conversion of angiotensin I to angiotensin II. Effects include vasodilation, decreased aldosterone secretion,decreased water and sodium retention, and increased bradykinin. Drugs that interact with lisinopril include diuretics and NSAIDs, resulting in hypotension and renal damage, respectively. Lisinopril has no effect on codeine. Angiotensin II receptor antagonists ("sartan" drugs) are an improvement on this class of drugs; by directly blocking angiotensin II, they eliminate the unwanted bradykinin-induced side effects associated with ACE inhibitors. Lithium is an antipsychotic commonly used by patients with bipolar disorder. Lithium has a narrow therapeutic index and can cause serious renal and CNS toxicity. Metronidazole inhibits lithium clearance from the kidneys, resulting in high lithium blood levels. Renal toxicity can occur when diuretics and lithium are taken concurrently because of excessive sodium depletion. Lithium has no effect on codeine.

Which one of the following is not an antifungal? A. Nystatin B. Amphotericin B C. Ketoconazole D. Esomeprazole E. Griseofulvin

The correct answer is D. Esomeprazole (nexium) is an H+/K+ ATPase inhibitor that is used in the treatment of GERD or peptic ulcer disease. The rest are all antifungal that work through various different mechanisms

A 20-year-old man with no prior significant medical history visits his oral surgeon for wisdom tooth extraction with IV sedation. He was given IV midazolam during the procedure. Midway through the surgery, he suddenly becomes agitated and combative and exhibits involuntary movements. The surgeon determines that this is likely due to dis inhibition reaction to the benzodiazepine. Which one of the following medication can be used to reverse the effect of midazolam? A. Naloxone B. Naltrexone C. Protamine D. Flumazenil E. Insulin

The correct answer is D. Flumenazil is a benzodiazepine antagonist used to treat in the case of overdose. Naloxone and naltrexone are opioid receptor antagonists. Protamine is an antidote for heparin overdose. Insulin is used to treat hyperglycemia

A patient presents to your office for an initial visit. When reviewing the patient's medical history, the patients tells you that she is taking 81mm of aspirin once a day and several alternative medications.She does not specify which alternative medications she is taking because she assumes they are not necessary for you to know. In fact, it is important for dentists to know about all medications and supplements to protect patients from possible substance interactions. When planning for a surgical procedure, which of the following alternative medications might you want to discontinue to prevent excessive bleeding in this patient? A. Ginseng B. Echinacea C. St. John's Wort D. Ginkgo Balboa E. Capsaicin

The correct answer is D. Ginkgo balboa is mainly used as a memory and concentration enhancer and to treat circulatory disorders. Like many alternative medications, there is much conflicting research on its effectiveness. Some laboratory studies have shown that ginkgo balboa improves blood circulation by dilating blood vessels and blocking the effects of platelet-activating factor. Because of its potential effect to improve blood flow, ginkgo balboa is often taken by patients with intermittent claudication (pain caused by inadequate blood flow to the legs). Because ginkgo balboa decreases the aggregation ability of platelets, there is some concern that its use, particularly when combined with other anticoagulants, such as aspirin, puts patients at increased risk of bleeding. Of special concern is the increased risk of intracranial hemorrhage. Ginseng has multiple traditional uses including: improving recovery from illness and well being, treating erectile dysfunction, hepatitis C, and symptoms associated with menopause, lowering blood sugar, and controlling blood pressure.Given the diversity of its uses, it may be taken by many patients who believe in the use of complementary medicine. The most common side effects of ginseng are headaches and GI upset. An important precaution in the use of ginseng should be given to patients with diabetes because of its potential to lower blood sugar. Echinacea is traditionally used to treat or prevent colds or the flu by boosting the immune system. Side effects include allergic reactions or GI upset.St. John's Wort is one of the most commonly used herbal supplements in the United States.It is used to help mild-to-moderate depression.It can enhance the effects of anesthesia, and because St. John's Wort induces CYP3A4 in the gut and liver, it may decrease the metabolism of other CYP3A4 substrates, which includes at least half of marketed medications, including some anesthetics. Capsaicin is the active ingredient in chili peppers. It is usually used in a topical cream form to relieve pain and itching. For instance, a dental practitioner may recommend it to patients with postherpetic neuralgia. Capsaicin works by depleting substance P, a neurotransmitters that signals pain. Side effects of capsaicin include a burning sensation in the area it is applied, redness, and skin blisters.

Continuous infusion of medication A is given to a 65-kg patient. The pharmacokinetic parameters are as follows: clearance=9mL/min/kg, volume of distribution = 65 L, half-life = 4 hours.How long will it take for the medication level to reach 93.75% of steady state? A. 8 hours B. 10 hours C. 14 hours D. 16 hours E. 18 hours

The correct answer is D. It takes one half-life to get to 50% of steady state, two to reach 75%, and four to reach 93.75%. Therefore, four half-lives are 4×4 hours, which is a total of 16 hours. Each successive half-life brings the level of medication A closer to 100%.

Misoprostol can be used for the following,except: A. Abortion B. Induction of labor C. Prevention of NSAID-induced peptic ulcer disease D. Rheumatoid arthritis E. Maintenance of patent ductus arteriosus (PDA) in newborns with certain congenital cardiovascular defects

The correct answer is D. Misoprostol is a synthetic prostaglandin E1 analog that can be used for abortion, labor induction, prevention of NSAID-induced gastric ulcers, and maintenance of PDA in certain cardiac congenital defects.

A 50-year-old patient with recent diagnosis of hypertension presents to your clinic complaining of a sudden increase in the size of his tongue and slight difficulty in breathing. He was recently started on an antihypertensive medication. Which one of the following drug classes may have caused the patient's presentation? A. Beta-blocker B. Alpha 1-blocker C. Thiazide diuretic D. Angiotensin-converting enzyme (ACE) inhibitor E. Calcium channel blocker

The correct answer is D. Patient here presents with angioedema, a side effect of ACE inhibitors such as captopril, enalapril, and lisinopril. ACE inhibitors decrease the conversion of angiotensin I into angiotensin II, thereby preventing vasoconstriction and resultant increase in aldosterone. It is commonly used in the treatment of hypertension, especially in the context of other comorbidities such as diabetes mellitus. Other adverse effects of ACE inhibitors include cough, hyperkalemia, rash, taste changes, orthostatic hypotension, and liver toxicity. ACE inhibitors are contraindicated during pregnancy because of their potential for teratogenicity.

Which one of the following is an ester local anesthetics? A. Bupivacaine B. Lidocaine C. Mepivacaine D. Tetracaine E. Prilocaine

The correct answer is D. Tetracaine is a longacting ester local anesthetics. The rest of the options are all amides.

A patient presented to your office for an emergency visit. One side of the patient's face was swollen, and on examination, a small abscess was present apical to tooth #3. The abscess was incised and drained, penicillin was prescribed, and root canal treatment was recommended. The next day, the patient calls your office and complains of swollen lips and a developing rash. The best response to this situation is to: A. Tell the patient not to worry; this is a normal reaction B. Prescribe epinephrine C. Instruct the patient to discontinue the penicillin and prescribe amoxicillin instead D. Instruct the patient to discontinue the penicillin and prescribe clindamycin instead

The correct answer is D. The symptoms that patient describes are representative of an allergic reaction to a drug, in this case, penicillin. Clindamycin is a lincosamide antibiotic,typically used to treat anaerobic infections. In patients with hypersensitivity to penicillins, clindamycin may be used to treat infections caused by susceptible aerobic bacteria as well. It is also used to treat bone and joint infections, particularly those caused by Staphylococcus aureus.Amoxicillin would be an inappropriate alternative as it is from the same family of antibiotics as penicillin.

A 55-year-old female patient was referred to your office by her physician because she is preparing to receive an infusion of zoledronic acid.Her physician told her to see a dentist to determine if she has any teeth that may need to be extracted in the near future. If so, these should be extracted prior to the infusion because of the risk of poor bone healing (osteonecrosis) that sometimes occurs in patients receiving infusions of zoledronic acid. Prior to the infusion, the patient was taking an oral form of this type of drug.What is another major side effect of the oral form that her physician may have warned her about? A. Anemia B. Xerostomia C. Edema D. Esophageal perforation E. Orthostatic hypotension Pharmacology

The correct answer is D. Zoledronic acid is an example of a bisphosphonate used to treat conditions of the bones, such as osteoporosis,osteopenia, Paget disease, or hypercalcemia of malignancy. Bisphosphonates are antibone resorbers that work by inhibiting the actions of osteoclasts. Side effects of bisphosphonates include: irritation of the esophagus (potentially causing perforations), headaches, muscle and joint pain, constipation, diarrhea, flatulence,dysphagia, and risk of osteonecrosis. Choice D is therefore the best answer. To best reduce the incidence of esophageal perforation, it is recommended to take the oral drugs in the morning with a full glass of water at least 30minutes prior to intake of any other substance and to sit or stand for at least 30 minutes after ingestion of the drug.Drug-induced hemolytic anemia may occur when a drug causes the immune system to react against its red blood cells. Drugs that may have this effect include: cephalosporins and penicillins,levodopa (used to treat Parkinson disease),methyldopa (an alpha-2 agonist used to treat hypertension) quinidine, and some antiinflammatory drugs. Xerostomia, or dry mouth, is not a disease, rather a symptom of other medical conditions or a side effect of numerous medications.The major classes of drugs that cause xerostomia are antihistamines, antidepressants, anticholinergics,antihypertensives, antipsychotics,anti-Parkinson agents, diuretics, sedatives, and anorexiants.Edema is defined as the retention of fluid in an organ or in the body that results in swelling. Drugs that may cause edema include chemotherapy agents (such as rituximab that is also used for rheumatoid arthritis) and corticosteroids(such as prednisone).Orthostatic hypotension (or postural hypotension) occurs when there is a sudden drop in blood pressure. This side effect is often seen in patients taking drugs that have an alpha-1 blocking effect. Drugs with this effect include those used to treat hypertension, such as alpha-blocking agents (i.e., terazosin), mixed alpha- and beta-blocking agents (i.e., carvedilol,labetalol), calcium channel blockers (i.e., nifedipine,verapamil), and antidepressants, both tricyclics(i.e., amitriptyline) and monoamine oxidase inhibitors (i.e., phenelzine).

A female patient presents to your office with facial and torso obesity, facial hair growth, and a deepened voice. The patient explains these changes occurred when she started taking a common drug to treat Crohn's disease, and subsequently she recently discontinued the drug use.While performing a surgical extraction, the patient suddenly starts breathing at a fast rate,sweating, and complains of nausea and chills.You recognize that the patient is experiencing a crisis and reach for your Emergency Kit. Which of the following contents of your Emergency Kit would be most appropriate to alleviate this crisis? A. Oxygen B. Epinephrine C. Nitroglycerin D. Sugar E. Hydrocortisone

The correct answer is E. Crohn's disease is a chronic inflammatory condition that can affect the entire digestive system. There is no cure for this disease; its symptoms can be minimized and sent into remission with anti-inflammatory medications and immune modulators. On the basis of the symptoms this patient has experienced as a side effect of taking a drug to treat her Crohn's disease, it is likely that she had been taking a systemic corticosteroid to reduce inflammation.Long-term use of corticosteroids can suppress the ability of the adrenal glands to produce natural cortisol and as a result when these drugs are discontinued abruptly, the body can display symptoms of adrenal insufficiency (adrenal crisis),like the patient above did during the dental procedure, because of a lack of natural cortisol.To prevent the above scenario, gradually taper the dose when discontinuing corticosteroids and take an extra dose prior to stressful situations for up to 2 years after discontinuing the drug.The best answer choice would be Hydrocortisone(2-mL dose), an artificial corticosteroid,which would temporarily relieve the symptoms of adrenal insufficiency.Oxygen is useful in every emergency, with the exception of hyperventilation. Oxygen would have been helpful to get the patient through the symptoms of the adrenal crisis; however, it would not have been sufficient to alleviate the crisis.Epinephrine is the drug of choice to treat anaphylaxis in the dental chair. Signs of anaphylaxis would include flushing and itching of the skin, feelings of anxiety, rapid pulse, and difficulty breathing. Epinephrine is typically given intramuscularly and has a very rapid onset and short duration of action. Epinephrine can also be used to treat an asthma attack that does not initially respond to a beta-2 agonist such as albuterol. Nitroglycerine is used in the case of acute angina attack or myocardial infarction in the dental office. It is given sublingually, as a tablet or spray, and has a rapid onset. When a patient experiences signs of angina, one dose should be given. If relief does not occur, second and third doses can be given at 5-minute intervals. It is also useful to have an automated external defibrillator (AED) available in the office in the case of cardiac arrest.Sugar, either in an oral form or injectable form, is indicated for the management of hypoglycemia.Conscious patients will be able to take an oral source of sugar, such as fruit juice,whereas unconscious patients will require IM glucagon or IV dextrose. When treating diabetic patients, it is important to ask about their most recent HBA1c and daily blood glucose levels and to be aware of their risk of hypoglycemia, as often times patients will take their medications for diabetes and then skip a meal prior to their dental visits

After taking Drug X for 5 days, steady free blood levels average about 20 ug/mL. Drug Z is then introduced while the patient continues to take Drug X, and the free blood levels of Drug X increase to 100 ug/mL. What could have accounted for this? A. DrugZis a livermicrosomal enzyme inducer B. Drugs X and Z formed a chelation product in the intestine C. Drug Z increased the glomerular filtration rate D. Drug Z has a positive inotropic and chronotropic effect E. Drugs X and Z are highly bound to plasma proteins

The correct answer is E. If Drugs X and Z both have a tendency to be highly bound to plasma proteins, then when Drug Z is introduced there would be an increased competition for protein binding sites. This would cause displacement of Drug X from plasma proteins, and the result would be increased free Drug X in the plasma,resulting in increased free blood levels of Drug X. An example of this interaction occurs when aspirin is introduced in a patient who is currently taking warfarin. Drugs that induce liver microsomal enzymes increase their activity. If Drug Z was an inducer,and assuming that Drug X was a substrate of liver microsomal enzymes, then increasing the activity of the enzymes would speed up the metabolism of Drug X. If Drug X was metabolized more rapidly, decreased blood levels of Drug X would be expected.If Drugs X and Z formed a chelation product in the intestine, this would result in decreased free levels of Drug X. For example, when a patient taking tetracycline also takes an antacid (or ingests any food product containing divalent and trivalent cations), the components of the antacid will form a chelation product with tetracycline. When tetracycline is bound to another molecule through chelation, this translates to decreased free levels of tetracycline, resulting in decreased absorption of tetracycline and decreased effectiveness.If Drug Z increased the glomerular filtration rate, and it was assumed that Drug X was excreted via the kidneys, this would result in more rapid excretion of Drug X. If the elimination of Drug X is increased, then the free blood levels of Drug X are decreased.If Drug Z has a positive inotropic and chronotropic effect, this would have little effect on the blood levels of Drug X. Positive inotropic drugs (examples include digoxin, epinephrine, and amrinone) increase the strength of muscle contraction of the heart. Positive chronotropic drugs (examples include atropine, dopamine,and epinephrine) increase heart rate. While both of these types of agents may increase blood flow through the body, they have no effect on the concentration of drugs in the blood.

A patient with uncontrolled asthma may be taking multiple medications to attempt to control the disease. Which of the following best describes the mechanism of action of montelukast? A. Beta-2 adrenergic agonist B. Leukotriene receptor antagonist C. Lipoxygenase pathway inhibitor D. Muscarinic receptor antagonist E. Corticosteroid used to reduce inflammation F. Suppresses the cough reflex

The correct answer is E. Montelukast (singulair) is a leukotriene receptor antagonist used for the prophylactic and chronic treatment of asthma and seasonal allergies. Leukotrienes are released by inflammatory cells and cause the following symptoms in asthma: hypersecretion of mucus, decreased mucus transport and mucosal accumulation, bronchoconstriction and airway narrowing, and infiltration of inflammatory cells in the airway wall. These symptoms are decreased by drugs that competitively inhibit the binding of leukotrienes to their receptors. Montelukast is not useful for the treatment of acute asthma attacks. Albuterol is an example of a short-acting beta- 2 adrenergic agonist, which causes smooth muscle relaxation resulting in bronchodilation. It can be used for acute asthma attacks. Albuterol is most often given in the inhaled form using a nebulizer. Zileuton is an example of a lipoxygenase pathway inhibitor. This drug blocks leukotriene synthesis by competitively inhibiting 5-lipooxygenase, an enzyme that catalyzes the formation of leukotrienes from arachidonic acid via oxygenation. Zileuton is not useful for the treatment of acute asthma attacks. Zileuton is a weak inhibitor of CYP1A2 and therefore has significant drug interactions with CYP1A2 substrates such as warfarin and theophylline. Zileuton also causes elevations of liver enzymes (AST, ALT).Ipratropium is an anticholinergic agent. By blocking muscarinic receptors, this drug inhibits bronchoconstriction and mucus secretion. It does not diffuse through the blood, preventing any potential systemic side effects, including cardiac effects and is therefore safe to use in patients with heart disease. It is not as powerful as the beta-2 adrenergic agonists but can be used along with a beta-2 agonist in the case of acute asthma attacks. It is sometimes associated with dry mouth. Triamcinolone is an example of a glucocorticoid. Glucocorticoids are effective in treating asthma because of their anti-inflammatory effects.Inhaled forms of glucocorticoids eliminate systemic side effects, but occasional reports of local candidiasis do occur. Benzonatate is an antitussive agent that works by depressing the medullary cough center and exerting an anesthetic action on the respiratory mucosa. It is unrelated to narcotic antitussive agents such as codeine.

Your 55-year-old male patient is scheduled for three quadrants of periodontal surgery. Each surgical procedure is scheduled 4 weeks apart. This patient is allergic to penicillin and has a history of a mitral valve prolapse. On the basis of the current guidelines, which prescription would be most appropriate to adequately premedicate this patient for all of his visits? A. Amoxicillin 2-g tablets; Disp: 3 tablets; Sig: take 1 tablet 30-60 minutes prior to dental procedure B. Amoxicillin 2-g tablets; Disp: 6 tables; Sig: take 2 tablets 30-60 minutes prior to dental procedure C. Clindamycin 600-mg tablets; Disp: 3 tablets; Sig: take 1 tablet 30-60minutes prior to dental procedure D. Clindamycin 600-mg tablets; Disp: 6 tablets;Sig: take 2 tablets 30-60 minutes prior to dental procedure E. No prescription necessary

The correct answer is E. The American Heart Association guidelines for antibiotic prophylaxis were revised in April 2007. According to the new guidelines, patients requiring prophylaxis include those with a history of prosthetic cardiac valve, history of previous infective endocarditis,history of congenital heart disease, and history of cardiac transplantation resulting in cardiac valvulopathy. It is no longer recommended to prescribe antibiotics for those patients with a history of mitral valve prolapse. The guidelines also define which procedures do and do not require antibiotic prophylaxis. Periodontal surgery would require antibiotic prophylaxis, along with any procedure that involves manipulation of gingival tissue, the periapical region of teeth, and the perforation of the oral mucosa. Procedures that do not require antibiotic prophylaxis include: routine anesthetic, injections through non infected tissue, taking dental radiographs,placement of removable prosthodontic or orthodontic appliances, adjustment of orthodontic appliances, placement of orthodontic brackets, shedding of deciduous teeth, and bleeding from trauma to the lips or the oral mucosa. The guidelines did not change for those patients with a history of prosthetic joint replacement. In the case that a patient has one of the four conditions requiring antibiotic prophylaxis and had no allergy to penicillin, 2 g of amoxicillin would be an appropriate prescription to cover the patient for the three different surgical procedures.Four grams of amoxicillin would be more than necessary to give for antibiotic prophylaxis prior to each procedure.Patients who have one of the four conditions requiring antibiotic prophylaxis and who are also allergic to penicillin require 600 mg of clindamycin 1 hour prior to their surgical procedures. Twelve hundred milligram of clindamycin would be more than necessary to give for antibiotic prophylaxis prior to each procedure.

A new antibiotic is being tested in a clinical trial.The following pharmacokinetic parameters are listed as follows: Clearance = 200 mL/min, volume of distribution (Vd) = 50 L, half-life =6 hours. Assuming that the drug is being administered intravenously, what loading dose (LD)should be given to the patient to reach a plasma concentration (Cp) of 5 mg/L? A. 50 B. 100 C. 150 D. 200 E. 250

The correct answer is E. The loading dose (LD) is a function of the volume of distribution (Vd) and the desired drug level in the plasma. In this case, LD = Vd × Cp = 50 L × 5 mg/L = 250 mg.

Which one of the following anticonvulsants is known to cause neural tube defects in unborn fetus? A. Phenytoin B. Carbamazepine C. Gabapentin D. Benzodiazepines E. Valproic acid

The correct answer is E. Valproic acid is an anticonvulsant that blocks sodium channels and increases GABA concentration. It is also used for rapid cycling andmixed affective disorders as mood stabilizer. Side effects include hepatotoxicity,hemorrhagic pancreatitis, thrombocytopenia, and neural tube defects

Accidental ingestion of warfarin can lead to elevated PT and PTT. Which one of the following is the most appropriate treatment? A. Vitamin A B. Vitamin B C. Vitamin C D. Vitamin D E. Vitamin K

The correct answer is E. Warfarin interferes with synthesis of vitamin K-dependent coagulation factors (II, VII, IX, X). This could lead to increased clotting time for both extrinsic (PT)and intrinsic (PTT) coagulation pathways. Vitamins A, B, C, and D are not directly involved in the coagulation cascade.

Amoxicillin tablets come in which of the following dosage forms? a. 250mg b. 500mg c. 1,000mg (1 gram) d. 2,000 mg (2 grams)

The correct answer is b. It is important to know which dosage forms of prescribed medications so that a pharmacist will honor your prescription. Amoxicillin oral tablets are available in 500mg or 875mg doses. Amoxicillin capsules are available in 250mg and 500mg doses. When prescribing for antibiotic prophylaxis, it is common to have a patient take 4 amoxicillin 500mg tablets.

A drug ending in -artan is likely what class of antihypertensive medication? a. Beta blocker b. Calcium channel blocker c. Angiotensin II receptor blocker d. Angiotensin converting enzyme (ACE) inhibitor

The correct answer is c. The name of a hypertension medication can often give a hint as to the drug's class. Beta blockers (-olol), calcium channel blockers (-ipine), angiotensin receptor blockers (-artan), ACE inhibitors (-pril) are drugs which often follow a pattern

All of the following are potential side effects/complications of lisinopril EXCEPT one. Which is the exception? a. Cough b. Dizziness c. Xerostomia d. Angioedema e. Hypotension f. Tardive dyskinesia g. Lichenoid drug reactions

The correct answer is f. Lisinopril is an ACE inhibitor. ACE inhibitors can be associated with a variety of side effects including a dry cough, angioedema, and lichenoid drug reactions as well as others. But ACE inhibitors are NOT associated with involuntary movements such as tardive dyskinesia

A 40-pound child presents to your office for a pulpotomy and placement of a stainless steel crown on tooth #L. What would be the approximate maximum recommended dose of 2% lidocaine? A. 1 carpule B. 2 carpules C. 3 carpules D. 4 carpules E. 5 carpules

The correct answer isC. The first step is to determine the local anesthetic concentration of 2% lidocaine present in one carpule on the basis of one carpule containing 1.8 mL of fluid. The following formula is used: 2% = 2 g/100 mL =2,000 mg/100 mL = 20 mg/mL; 20 mg/mL ×1.8 mL/carpule = 36 mg/carpule. There are 36 mg/carpule in a 2% solution of lidocaine. The next step is to take into account the maximum recommended dosage (MRD) for lidocaine,which is 2.0 to 3.2 mg/lb (or 4.5-7.0mg/kg). For a 40-pound child, 40 lb × 2.0 to 3.2 mg/lb = 80 to 128 mg. On the basis of this range and the knowledge that there are 36 mg/carpule in a 2% lidocaine solution, the following formulas are used: 80 mg/36 mg/carpule=2.2 carpules and 128 mg/36 mg/carpule = 3.5 carpules. The high end of the acceptable range is 3.5 carpules;therefore, three carpules would be an acceptable volume to administer.One and two carpules would be acceptable amounts of anesthetic to give; however, it would not be the maximum recommended dose.Four and five carpules are greater than the acceptable range for the maximum recommended dose.

All of the following statements are correct regardin penicillin, except: A. Penicillin is a bactericidal antibiotic that works by binding to penicillin-binding protein,and blocking transpeptidase from crosslinking peptidylglycine in bacterial cell wall B. Not all penicillins are effective against Pseudomonas aeruginosa C. Amoxicillin can cover both Escherichia coli and Haemophilus influenzae D. Combined with clavulanic acid or tazobactam,penicillins possess anti-beta lactamase activity E. Penicillin is a bacteriostatic antibiotic that works by inhibiting bacterial protein synthesis

The correct answer isE. Penicillin is a bactericidal antibiotic (not bacteriostatic) that works by binding to penicillin-binding protein and blocking transpeptidase from crosslinking peptidylglycine in bacterial cell wall. Not all penicillins are effective against Pseudomonas aeruginosa. Antipseudomonal penicillins include piperacillin, carbenicillin, and ticarcillin. Amoxicillin has an extended spectrum that is able to cover E. coli, Haemophilus influenza,Proteus mirabilis, Listeria monocytogenes,and Salmonella.By adding clavulanic acid or tazobactam to penicillins, the antibiotics are rendered beta-lactamase resistant.

vit K antagonist

Warfarin (Coumadin); OD= gingival bleeding

difference bt anaphylactoid and anaphylaxis

anaphylactoid has no IGE; direct action of drug on mast cells

What is type 2 hypersensitivity?

antibody dependent cytotoxicity; antingen AB binding; anemia thrombocytopenia

what type drugs cause gingival enlargement

anticonvulsants: phenytoin calcium channel blockers: immunosuppressive; cyclosporin

drugs that cause color changes in oral mucosa

antidiarrheals centrally acting antihypertensives antibiotics oral contraceptives antiarrhythmic antivirals

what is type 4 hypersensitivity

cell mediated or delayed hypersensitivity; antigens activate T cells; contact dermatitis of SED

volume of distribution is affected by

changes in blood flow, body composition and protein binding

What is hypogeusia?

decreased taste sensitivity

What is dysgeusia?

distortion of taste

what does half life determine

dosing interval

what is hemorrhagic crusting of the lips

erythema multiforme

what does half life assume

first order elimination a constant proportion of dose eliminated per unit of time

Diuretics

hydrochlorothiazide furosemide edema

what is a type B adverse drug reaction?

hypersensitivity; cannot be predicted

what is an example of type A reaction

hypotension from lisinopril

what is type 3 hypersensitivity?

immune complex; think blood transfusion without proper type of blood; serum sickness

lipophilic drugs have what type of VD

large

what is half life

length of time required for concentration of drug in the blood stream to be reduced to half of the original concentration

volume of distribution determines

size of initial or loading dose of the drug to achieve a target concentration

what does clearance represent

the intrinsic ability of organs to eliminate drug from blood

what does clearance determine

the size of the daily maintenance dose required to maintain a target concentration

What is aguesia?

total loss of taste

what is clearance

volume of blood from which drug is removed over time