Comp. A. Section 1. Chapter 6: Pharmacology

Which antibiotic is contraindicated in pregnant patients? A Tetracycline B Erythromycin C Penicillin D Amoxicillin

ANS: A Tetracycline (A) should not be used in pregnant women because of the effect it can have on the developing teeth and skeleton of the fetus. **Erythromycin (B), penicillin (C), and amoxicillin (D) are not associated with teratogenicity and therefore are commonly used in pregnant women.

Which drug is a common calcium channel blocker? A Verapamil (Calan, Isoptin). B Furosemide (Lasix). C Warfarin (Coumadin). D Lovastatin (Mevacor).

ANS: A Verapamil (Calan, Isoptin) (A) is a common calcium channel blocker. **Furosemide (Lasix) (B) is a loop diuretic. **Warfarin (Coumadin) (C) is an oral anticoagulant. **Lovastatin (Mevacor) (D) is a hydroxymethylglutaryl coenzyme A reductase inhibitor.

Which drug has the broadest antibacterial spectrum? A Amoxicillin (Amoxil) B Clavulanic acid (in Augmentin) C Dicloxacillin (Dynapen) D Penicillin G (Pfizerpen) E Penicillin V (Penicillin VK)

ANS: A Amoxicillin (Amoxil) (A) is the penicillin with a broadest spectrum of action and is called an "extended-spectrum" penicillin because it has greater activity compared with the other penicillin's listed against gram-negative bacilli. **Clavulanic acid (in Augmentin) (B) is not a penicillin, although its structure resembles penicillin with a beta lactam ring, it has little antibacterial effect by itself. It is a beta lactamase inhibitor and is added to amoxicillin to prevent amoxicillin's destruction by bacterial penicillinases. **Dicloxacillin (Dynapen) (C) is a narrow-spectrum penicillin but is resistant to some penicillinases. **Penicillin G (Pfizerpen) (D) and penicillin V (Penicillin VK) (E) have both have essentially the same narrow spectrum of action against many gram-positive bacteria and some gram-negative cocci. Although less active than penicillin G and penicillin V, dicloxacillin's resistance to penicillinase makes it useful in the treatment of infections caused by penicillinase-producing Staphylococcus aureus.

Which drug's antimicrobial action is based on its ability to inhibit cross-linking of the peptidoglycan chains in bacterial cell walls? A Amoxicillin (Amoxil) B Clindamycin (Cleocin) C Clarithromycin (Biaxin) D Ciprofloxacin (Cipro) E Gentamicin (Garamycin)

ANS: A Amoxicillin (Amoxil) (A), like other penicillin's, inhibits the enzyme transpeptidase, which catalyzes cross-linking in bacterial cell walls. **Clindamycin (Cleocin) (B), clarithromycin (Biaxin) (C), and gentamicin (Garamycin) (E) all inhibit ribosomal protein synthesis in bacteria. Ciprofloxacin (Cipro) (D) inhibits deoxyribonucleic acid (DNA) function by inhibiting DNA enzymes.

Each of the following is a possible side effect of an anticholinergic drug EXCEPT one. Which one is the EXCEPTION? A Salivation B Constipation C Mydriasis D Tachycardia

ANS: A Anticholinergic drugs prevent secretions such as saliva (A). **Anticholinergics antagonize the cholinergic system, and this may result in side effects such as constipation (B), mydriasis (C), and tachycardia (D).

Albuterol (Proventil, Ventolin) is a short-acting beta 2-agonist that can be administered via a metered-dose inhaler. Albuterol (Proventil, Ventolin) is recommended as an emergency treatment for dental patients who experience in-office asthma attacks. A Both statements are true. B Both statements are false. C The first statement is true, and the second statement is false. D The first statement is false, and the second statement is true.

ANS: A Both statements are true (A) because Albuterol (Proventil, Ventolin) is a beta 2-agonist drug that is used treat asthma. It is administered via a metered-dose inhaler for the treatment of intermittent asthma or an acute attack. Albuterol (Proventil, Ventolin) is used by dental offices as an emergency drug for dental patients who suffer an acute asthma attack. **Choices B, C, and D do not accurately reflect the statements.

Which drug is associated with xerostomia? A Cyclobenzaprine B Tetracycline C Clindamycin (Cleocin) D Cyclosporine (Sandimmune)

ANS: A Cyclobenzaprine (Flexeril) (A) is a muscle relaxant, which is associated with xerostomia. **Tetracycline (B) is associated with discoloration of developing teeth. **Clindamycin (Cleocin) (C) is associated with pseudomembranous colitis. **Cyclosporine (Sandimmune) (D) is known to cause gingival enlargement.

Which drug is commonly used as an antitussive? A Dextromethorphan B Pentazocine (Talwin-NX) C Propoxyphene (Darvon, Darvocet N-100) D Diphenoxylate ]

ANS: A Dextromethorphan (A), an opioid-like compound, is commonly used as an antitussive; it is the "DM" found in cough syrups. **Pentazocine (Talwin-NX) (B) is a narcotic used to treat mild to moderate pain. **Propoxyphene (C) is found in Darvocet N-100 and is used to treat mild to moderate pain. **Diphenoxylate (D), combined with atropine, is found in Lomotil and is used in the treatment of diarrhea.

Which agent is used to treat ONLY allergen-induced asthma? A Omalizumab (Xolair) B Cromolyn (Intal, Nasalcrom) C Fluticasone (Flovent) D Zileuton (Zyflo)

ANS: A Omalizumab (Xolair) (A) is the first of a new class of medications used to treat allergen-induced asthma. **Cromolyn (Intal, Nasalcrom) (B) is effective only for the prophylaxis of asthma. **Fluticasone (Flovent) (C) is an inhaled corticosteroid used to control symptoms in patients with mild, moderate, or severe persistent asthma, but not specifically allergen-induced asthma. **Zileuton (Zyflo) (D) is a 5-lipoxygenase inhibitor, which prevents the synthesis of leukotrienes.

Which drug should NOT be given to a patient with a true allergy to codeine? A Oxycodone (Percodan, Percocet, Tylox) B Buprenorphine (Buprenex) C Pentazocine (Talwin-NX) D Propoxyphene (Darvon)

ANS: A Oxycodone (Percodan, Percocet, Tylox) (A) should not be given to a patient with a true codeine allergy because it is a member of the morphine/codeine group of opioid analgesics, which are likely to exhibit cross-allergenicity. **Buprenorphine (Buprenex) (B) is not related to any of the other opioid groups and is unlikely to cause cross-allergenicity. **Pentazocine (Talwin-NX) (C) is a member of the morphine group. **Propoxyphene (Darvon) (D) is a member of the methadone group, so cross-allergenicity is unlikely.

31. Which oral antidiabetic agent needs to be administered for 6 to 14 weeks to reach its maximal therapeutic effect? A Rosiglitazone (Avandia) B Tolbutamide (Orinase) C Exenatide (Byetta) D Glimepiride (Amaryl)

ANS: A Rosiglitazone (Avandia) (A) may take up to 6 to 14 weeks to achieve its maximum effect. **Tolbutamide (Orinase) (B) and glimepiride (Amaryl) (D) work much faster than rosiglitazone. **Exenatide (Byetta) (C) is not an oral antidiabetic agent; it is administered through subcutaneous injection.

A patient being treated for xerostomia with pilocarpine (Salagen) is most likely to experience which side effect? A Sweating B Tachycardia C Urinary retention D Hypertension E Constipation

ANS: A Sweating (A) is the most common complaint of patients taking muscarinic cholinergic receptor agonists such as pilocarpine (Salagen) for the treatment of xerostomia. Although innervated by the sympathetic nervous system, sweat glands have muscarinic receptors that respond to postganglionic cholinergic nerves, resulting in increased secretion and these receptors also respond to pilocarpine. Cholinergic postganglionic nerves are otherwise rare in the sympathetic nervous system. **Although tachycardia (B) is a possibility because of vasodilation, the vasodilation is usually mild or nonexistent with the oral doses used in this situation. **Muscarinic receptor stimulation would tend to have very mild effects opposite to urinary retention (C) and constipation (E). **Hypertension (D) is not likely to occur with the effect of pilocarpine, since cholinergic agonists usually decrease blood pressure and slow heart rate.

All of the following drugs would be contraindicated in patients with peptic ulcers EXCEPT one. Which one is the EXCEPTION? A Aspirin B Acetaminophen C Ibuprofen D Pilocarpine

ANS: B Acetaminophen (B) does not cause gastrointestinal (GI) upset or bleeding and so is considered safe for patients with gastric ulcers. **Aspirin (A) and ibuprofen (C) both cause significant GI upset and gastric bleeding in a significant patient population and are contraindicated in patients with peptic ulcers. **Pilocarpine (D), a parasympathetic agonist, increases secretions, including gastric acid, exacerbating peptic ulcer symptoms; it is, therefore, contraindicated in these patients.

Which anesthetic has the longest duration of action? A Articaine (Septocaine) B Bupivacaine (Marcaine) C Lidocaine (Xylocaine) D Mepivacaine (Carbocaine) E Prilocaine (Citanest)

ANS: B Bupivacaine (Marcaine) (B) is chemically similar to mepivacaine but with an additional substitution that is highly lipid soluble. This change increases the potency and duration of the action of bupivacaine for up to 8 hours of analgesia, making it the longest acting local anesthetic that is commonly used in dentistry. **Articaine (Septocaine) (A) has a duration of action of 3 to 4 hours, making it an intermediate-acting local anesthetic. **Lidocaine (Xylocaine) without epinephrine (C) and mepivacaine (Carbocaine) (D) have a short duration of 30 to 90 minutes of analgesia. **Prilocaine (Citanest) (E) without epinephrine has an intermediate duration of 2 to 4 hours of analgesia.

In a patient suffering from chronic dry mouth (xerostomia) caused by Sjögren disease with some salivary gland function remaining, which drug would be MOST effective in stimulating salivary flow? A Amitriptyline (Elavil) B Cevimeline (Evoxac) C Oxymetazoline (Afrin) D Salmeterol (Serevent)

ANS: B Cevimeline (Evoxac) (B) stimulates muscarinic cholinergic receptors, directly stimulating saliva secretion from the salivary gland cells. **Amitriptyline (Elavil) (A), an antidepressant drug that blocks muscarinic receptors, would decrease salivary flow. **Oxymetazoline (Afrin) (C) stimulates alpha 2-adrenergic receptors and has much less effect on salivary flow compared with cevimeline. **Salmeterol (Serevent) (D) stimulates beta 2-adrenergic receptors and has little effect on salivary flow rate.

While obtaining a patient's medical history, the dental hygienist learns that the patient takes cimetidine (Tagamet) prescribed for peptic ulcer. Which is the MOST likely scenario if local anesthesia (LA) is administered? A LA is ineffective in therapeutic doses. B LA may cause systemic toxicity in therapeutic doses. C There is no change in the efficacy of LA. D LA causes an allergic reaction.

ANS: B Cimitidine (Tagamet) is a prototype of the H2-receptor antagonists which inhibit secretion of gastric acid by competitive inhibition of the H2-receptors of the parietal cells of the stomach. One of the most serious adverse effects of cimitidine is its ability to inhibit liver microsomal enzymes via the cytochrome P-450 enzymes, slowing the elimination of some drugs in blood plasma. This may lead to increased drug levels and toxicity (B), even when drugs such as lidocaine are given in therapeutic doses. The clinician should exercise caution and use the lowest possible dose of local anesthetic in patients on cimetidine. **Concurrent administration of cimitidine (Tagamet) would not negate lidocaine's local anesthetic properties (A). **The efficacy of lidocaine would be increased with administration of cimitidine (Tagamet) (C). **Allergic reactions to lidocaine are rare, and cimitidine (Tagamet) does not increase these types of reactions (D).

Curare-type drugs such as vecuronium (Norcuron) cause muscle relaxation by which mechanism? A Activating chloride channels in the CNS B Blocking nicotinic receptors at the skeletal neuromuscular junction C Reducing blood flow to the skeletal muscles D Reducing calcium release from intracellular storage sites in skeletal muscles E Blocking ganglionic transmission

ANS: B Curare-type drugs are competitive blockers of the nicotinic type of cholinergic receptors in the skeletal neuromuscular junction (B). **Activation of chloride channels (A), either through GABA or independently of GABA, is the mechanism that applies to many sedative hypnotics that have some ability to relax skeletal muscle. **Reducing blood flow (C) is not relevant to the action of any muscle relaxer. **Reducing calcium release from intracellular stores (D) is the mechanism of action of dantrolene (Dantrium), which is not a curare type drug. **Blocking ganglionic transmission (E) would be ineffective in causing skeletal muscle relaxation because skeletal muscles are innervated by somatic nerves, which do not have ganglia.

Epinephrine is combined with a local anesthetic to A enhance systemic local anesthetic absorption. B prolong the duration of action of the local anesthetic. C delay the onset of action of the local anesthetic. D increase the potency of the local anesthetic.

ANS: B Epinephrine (B) binds to alpha-receptors in the blood vessels and causes vasoconstriction, thus prolonging the action of the local anesthetic, decreasing the amount of blood flow to the local tissue, and reducing the potential for systemic toxicity. **Because of reduced blood flow to the area, there is actually a decrease in the systemic absorption (A) of the local anesthetic. **Epinephrine accelerates the onset of action (C) of the local anesthetic because it decreases its systemic absorption. **Epinephrine has no effect on the potency (D) of the local anesthetic.

30. Glucocorticoids should NOT be used to treat A pemphigus vulgaris. B herpetic gingivostomatitis. C erythema multiforme. D desquamative gingivitis.

ANS: B Glucocorticoids may exacerbate infections such as herpetic gingivostomatitis (B), which is a viral infection, and therefore are contraindicated for infectious oral lesions. **Pemphigus vulgaris (A), erythema multiforme (C), and desquamative gingivitis (D) are all noninfectious oral lesions, which are effectively treated with systemically administered steroids.

Each of the following is a characteristic of an ideal local anesthetic EXCEPT one. Which one is the EXCEPTION? A Reversible B Slow onset C Lack of systemic toxicity D Absence of local reactions

ANS: B In dentistry, a local anesthetic with a relatively rapid onset of action, not a slow onset (B), is required so that the time between the administration of the local anesthetic and the beginning of a painful dental procedure can be minimized. **Reversibility (A) of the actions of the local anesthetic is necessary so that the patient can regain normal sensation in the tissue. **Lack of systemic toxicity (C) is necessary for patient safety. **Local reactions (D) such as tissue irritation are considered unwanted and undesirable.

The U.S. Food and Drug Administration (FDA) has indicated that the maximum daily dose of acetaminophen (Tylenol) should be 3000 mg. Which is the major toxicity concern for acetaminophen that prompted this reduced dose? A Kidney disease B Liver toxicity C Excessive sedation D Asthmatic attacks E Bladder infections

ANS: B In high doses, acetaminophen may be converted to toxic radicals, which damage the liver (B). Patients with preexisting liver disease, those with alcoholism, and others are more susceptible. Acetaminophen poisoning accounts for a large number of emergency visits to the hospital, as well as many deaths as a result of liver damage. **Although kidney damage (A) has been associated with the use of nonnarcotic analgesics, these disorders have usually occurred after long-term chronic use and when combinations of these types of drugs have been used. **Acetaminophen does not have noticeable sedative (C) properties. It does not worsen asthma (D) unless an allergic reaction to acetaminophen occurs, which is rare. **There is no known link between acetaminophen and bladder infections (E), since the drug has no major effect on structures in the urinary tract.

Patients who have been prescribed ipratropium bromide (Atrovent), an anticholinergic drug for the treatment of chronic obstructive pulmonary disease (COPD) should be instructed to do what after each inhaler use? A Rinse with water, swish, and swallow after each inhalation B Rinse with water, swish, and expectorate after each inhalation C Rinse with water, swish, expectorate, and brush after each inhalation D Rinse with water, swish, expectorate, and brush after the morning inhalation only

ANS: B Ipratropium bromide (Atrovent) is an anticholinergic drug administered via a metered-dose inhaler and is the drug of choice for COPD. The side effects of ipratropium bromide include significant dry mouth (xerostomia), teeth staining, and taste alterations. Patients should be instructed to rinse the mouth with water, swish, and expectorate after each inhalation (B) to minimize these adverse effects and prevent excessive systemic absorption. **Patients should not swallow after rinsing and swishing (A) because it can cause a sore dry throat and exacerbate dry mouth. **Brushing is not necessary in addition to rinsing, swishing, and expectorating (C and D).

Which general anesthetic may cause respiratory acidosis with deeper levels of anesthesia? A Enflurane B Isoflurane C Sevoflurane D Halothane

ANS: B Isoflurane (B) causes irritation and significant respiratory acidosis. **Enflurane (A), sevoflurane (C), and halothane (D) are not associated with either excessive irritation or respiratory acidosis

Which of the following is the BEST choice of local anesthetic when performing a dental procedure on a pregnant patient? A Mepivacaine (Carbocaine) B Lidocaine (Xylocaine) C Bupivacaine (Marcaine) D Articaine (Septocaine)

ANS: B Lidocaine (Xylocaine) (C) is a category B drug (no evidence of risk in humans) and is the best drug choice for the pregnant patient. Mepivacaine (Carbocaine) (A), bupivacaine (Marcaine) (C), and Articaine (Septocaine) (D) are all pregnancy category C drugs; that is, there is a risk of fetal harm if the drug is administered.

Each of these drugs is used to treat asthma EXCEPT one. Which one is the EXCEPTION? A Fluticasone (Flonase) B Metoprolol (Lopressor) C Salmeterol (Serevent) D Ipratropium (Atrovent) E Montelukast (Singulair)

ANS: B Metoprolol (Lopressor) (B) is a selective beta 1-adrenergic receptor blocker. Beta-blockers are contraindicated in asthma because by blocking the beta 2-adrenergic receptors in the lung, bronchoconstriction may occur. Selective beta 1-adrenergic receptor blockers have primarily cardiac effects and are less likely to cause bronchoconstriction than nonselective beta-adrenergic receptor blockers. These drugs should still be used with caution in patients with asthma, since these drugs have no direct benefit in the relief of asthma symptoms. **Fluticasone (Flonase) (A) is a glucocorticoid, with an anti-inflammatory effect in the lung, reducing the inflammatory component of asthma. **Salmeterol (Serevent) (C) is a long-acting beta 2-adrenergic receptor agonist, which causes bronchodilation. **Ipratropium (Atrovent) (D) is an antimuscarinic, anticholinergic drug that blocks the broncho-constricting effect of acetylcholine that is released in the lung. **Montelukast (Singulair) (E) is a cysteinyl leukotriene 1 receptor blocker. Cysteinyl leukotrienes are inflammatory mediators that contribute to bronchoconstriction.

The drug metronidazole (Flagyl) is most useful in therapy for which oral condition? A Candidiasis B Aggressive periodontitis C Aphthous stomatitis D Xerostomia E Herpes labialis

ANS: B Metronidazole (Flagyl) is used clinically for two reasons: (1) treatment of certain parasitic diseases and (2) treatment of infections caused by anaerobic bacteria. Periodontal disease (B) typically involves anaerobic bacteria. Metronidazole is not effective against fungi such as Candida albicans and may increase the risk of oral candidiasis (A). Aphthous stomatitis (C) usually does not require medication. Xerostomia (dry mouth) (D) is not helped by metronidazole; the drug does not stimulate salivary flow. Metronidazole is not effective against Herpes simplex virus, the causative agent of cold sores (herpes labialis) (E).

Anti-inflammatory, antipyretic, and analgesic effects are associated with which drug? A Codeine B Ibuprofen C Hydrocodone D Acetaminophen

ANS: B Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (B) block the enzyme cyclooxygenase, which results in its anti-inflammatory, antipyretic, and analgesic effects. **Codeine (A) and hydrocodone (C) are opioids and have only analgesic effects. **Acetaminophen (D) has antipyretic and analgesic effects but no anti-inflammatory effect.

Which drug has the MOST potent anti-inflammatory effect? A Alendronate (Fosamax) B Prednisone (Deltasone) C Atenolol (Tenormin) D Raloxifene (Evista) E Fluoxetine (Prozac)

ANS: B Prednisone (Deltasone) (B), a glucocorticoid, has several mechanisms that make it a potent anti-inflammatory drug used in a variety of settings. Inhibition of phospholipase A2, a key enzyme in the inflammatory prostanoid and leukotriene pathway is a primary anti-inflammatory action. **Alendronate (Fosamax) (A) is a bisphosphonate that is used to reduce bone turnover. **Atenolol (Tenormin) (C) is a beta-adrenergic receptor blocker that has a number of cardiovascular effects but not an anti-inflammatory effect. **Raloxifene (Evista) (D) is an estrogen receptor agonist-antagonist, more commonly known as a selective estrogen receptor modulator (SERM), with a beneficial effect in the treatment of postmenopausal osteoporosis, but no anti-inflammatory action. **Fluoxetine (Prozac) (E) is a selective serotonin reuptake inhibitor (SSRI), whose action in the brain mediates its antidepressant effect.

Which drug is used to manage the nausea and vomiting caused by antineoplastic therapy? A Omeprazole (Prilosec) B Prochlorperazine (Compazine) C Cisplatin (Platinol) D Codeine

ANS: B Prochlorperazine (Compazine) (B) is a phenothiazine (antiemetic drug), which is used to control nausea and vomiting. **Omeprazole (Prilosec) (A) is a proton pump inhibitor used in the treatment of excessive stomach acid, not as an antiemetic. **Cisplatin (Platinol) (C) is an antineoplastic agent. **Codeine (D) is a narcotic analgesic, and nausea and vomiting are some of its side effects.

Second-generation antihistamines such as loratadine (Claritin) are less sedating than their predecessors in therapeutic doses because they A bind only to histamine 2 (H2)-receptors. B do not penetrate the blood-brain barrier. C are combined with decongestants for their central nervous system (CNS) stimulant activity.

ANS: B Second-generation antihistamines (B) cannot cross the blood-brain barrier to be distributed to the brain and therefore cause little to no sedation. **Although these drugs have some binding to H2-receptors (A), this is not the reason for their lack of sedating effects. **Second generation antihistamines (C) are not CNS stimulants, but they may be combined with decongestants to treat nasal congestion, not because of their stimulating effects.

53. Sumatriptan (Imitrex, Alsuma) is a drug that is commonly used to treat which disorder? A Hypercholesterolemia B Migraine headaches C Asthma attacks D Atrial fibrillation E Opioid toxicity

ANS: B Sumatriptan (Imitrex, Alsuma) is an agonist at serotonin 5HT1B/1D receptors. Sumatriptan and other triptans cause constriction of intracranial blood vessels, reduce pain fiber activity, and reduce inflammation associated with migraine headaches (B). The triptans have little effect at other receptors and the mechanism of action of sumatriptan has little benefit in the treatment of other disorders. **Sumatriptan does little to change cholesterol metabolism (A) or to reduce bronchoconstriction in asthma attacks (C). **Sumatriptan has no obvious benefit on ion channel activity in the heart (D) and may even be associated with certain arrhythmias. **Sumatriptan has no activity on opioid receptors (E).

Two cartridges of lidocaine (Xylocaine; 2% with 1:100,000 epinephrine) are to be administered to a dental patient. The patient is also receiving treatment for hypertension. What is the maximum safe dosage of epinephrine? A No safe dosage of epinephrine for patients with cardiovascular disease exists. B 0.4 mg epinephrine C 0.04 mg epinephrine D 0.2 mg epinephrine

ANS: C A dosage of 0.04 mg (C) epinephrine, found in two cartridges of lidocaine (Xylocaine) (2%) with 1:100,000 epinephrine, is the safest dose for patients with cardiovascular disease and is even termed "the cardiac dose." **In the past, vasoconstrictors were avoided in patients with cardiovascular disease (A) because of the drug's sympathetic nervous system effects in raising heart rate and blood pressure. Research has shown, however, that patients may produce far higher amounts of endogenous epinephrine if anesthesia is insufficient, so it is safer to control the dose. **Doses of 0.4 mg (B) and 0.2 mg (D) of a vasopressor are high enough to have an adverse effect on the cardiovascular system in a patient with disease.

Aspirin is approved to treat each of the following conditions EXCEPT one. Which one is the EXCEPTION? A Pain B Fever C Asthma D Arthritis E Dysmenorrhea

ANS: C Aspirin should not be used in persons with asthma (C) because this population is more likely to have a hypersensitivity reaction, with the incidence ranging from 5% to 15%. **Pain (A), fever (B), arthritis (D), and dysmenorrhea (E) are all approved indications for aspirin use.

Beriberi is caused by a severe deficiency of A ascorbic acid. B niacin. C thiamine. D folic acid.

ANS: C Beriberi is the result of a severe deficiency of thiamine (C). **Scurvy is caused by a deficiency of ascorbic acid (A). **Pellagra is produced by a deficiency of niacin (B). **Megaloblastic anemia is produced by a deficiency in folic acid (D).

Lithium (Eskalith, Lithobid) is commonly used in the treatment of A schizophrenia. B migraine headaches. C bipolar depression. D anxiety disorder. E obsessive-compulsive disorder.

ANS: C Bipolar depression (C) is commonly treated with lithium (Eskalith, Lithobid). **Antipsychotics are the drugs of choice for the treatment of schizophrenia (A). **Migraine headaches (B) are treated with propanol, and a variety of other medicines. **Anxiety disorder (D) and obsessive- compulsive disorder (E) are treated with antidepressants.

Drugs that inhibit hydroxymethylglutaryl coenzyme A (HMG CoA) reductase are often used to treat which type of disorder? A Arrhythmias (e.g., atrial fibrillation) B Hypertension C Blood lipid disorders (e.g., hypercholesterolemia) D Systemic fungal infections (e.g., candidiasis) E Osteoarthritis

ANS: C HMG CoA reductase is an important enzyme in the synthesis of cholesterol in the liver (C). Drugs such as Lovastatin (Mevacor) and other "statins" reduce plasma cholesterol by this mechanism. **Statins have a less direct effect on cardiac arrhythmias (A) and hypertension (B), although lowering plasma cholesterol often has a beneficial effect in patients receiving these agents. Statins have little if any effect on fungal organisms (D). **Statins do not treat the inflammation or the pain of osteoarthritis (E).

Lidocaine (Xylocaine) achieves anesthesia primarily by acting at which sites? A Dopamine receptors B Chloride channels C Sodium channels D Serotonin receptors

ANS: C Lidocaine (Xylocaine) binds to and blocks sodium channels (C), which results in inhibition of nerve membrane depolarization and prevention of nerve conduction to the central nervous system (CNS), causing reversible anesthesia. Local anesthetics such as lidocaine are often termed "sodium channel blockers." **Dopamine (A) and serotonin receptors (D) are targets of several drugs that work on the CNS. **Chloride channels (B) are targets of many sedatives.

The patient reports taking lisinopril (Prinivil) on the medication history. Each of the following is an indication for lisinopril (Prinivil) EXCEPT one. Which one is the EXCEPTION? A Chronic heart failure B Hypertension C Hypercholesterolemia D Arrhythmia E Recent history of myocardial infarction

ANS: C Lisinopril (Prinivil) is an angiotensin-converting enzyme (ACE) inhibitor, with multiple indications in treatment of cardiovascular conditions. ACE inhibitors do not have a significant effect on hypercholesterolemia (C). **Lisinopril reduces the load on the heart by vasodilation, which makes it useful in treating heart failure (A) by reducing the risk of deleterious vascular and cardiac remodeling. **By inhibiting the production of angiotensin II, lisinopril reduces blood pressure in hypertensive patients (B). **It is also indicated for patients with arrhythmias (D) and recent myocardial infarctions (E) to reduce the likelihood of subsequent cardiac events.

Which beverage should not be given concurrently with tetracycline? A Apple juice B Tomato juice C 2% milk D Carbonated soda

ANS: C Milk (C) contains calcium, a divalent cation, which reduces the intestinal absorption of tetracycline by forming nonabsorbable chelates of tetracycline. **Apple juice (A), tomato juice (B), and carbonated soda (D) do not interfere with tetracycline absorption.

Which is NOT a characteristic associated with nitrous oxide (NO) used for conscious sedation? A Has analgesic effect B Has ability for rapid induction of conscious sedation C Causes skeletal muscle relaxation D Is heavier than air E Is odorless

ANS: C NO is not an effective skeletal muscle relaxant (C) even at higher anesthetic doses. *NO has significant analgesic effects (A). **It is noted for rapid induction (B) because of its low blood-to-gas solubility coefficient. **NO is heavier than air (D) and may accumulate at floor level under conditions of poor ventilation or conditions of poor scavenging. **It is odorless (E) and tasteless to the patient.

Which of the following BEST describes the mechanism of action of phentolamine? A Reversal of calcium channel blockage B Blockage of calcium channels C Reversal of sodium channel blockage D Blockage of sodium channels

ANS: C Phentolamine is a drug that causes reversal of sodium channel blockage (C), shortening the time of soft tissue anesthesia following a dental procedure. The mechanism is related to its ability to block the vasoconstriction resulting from alpha-adrenergic receptor stimulation caused by epinephrine and norepinephrine. The resulting vasodilation leads to more rapid removal of the local anesthetic from the area of injection after the phentolamine is injected. **Reversal of calcium channel blockage (A) is not an action of phentolamine (OraVerse). **Calcium channel blockage (B) is the action of hypertensive medications such as verapamil (Calan, Isoptin). **Blockage of sodium channels (D) is the action of the local anesthetic agent, not phentolamine.

Which drug is used to prevent an attack of gout? A Colchicine B Aspirin C Probenecid D Codeine

ANS: C Probenecid (C) is used to prevent an attack of gout, as it blocks the tubular reabsorption of filtered urate, prevents new tophi, and mobilizes those present. **Colchicine (A) is used to treat an acute attack of gout. **Aspirin (B) is contraindicated for patients with gout because it may counteract the uricosuric effects of probenecid. **Codeine (D) is not a gout medication.

Which agent is an autocoid known for stimulating secretion from salivary glands? A Histamine B Pilocarpine C Substance P D Bradykinin

ANS: C Substance P (B) is an autocoid that stimulates secretion from salivary glands. **Histamine (A) and bradykinin (D) do not have the ability to stimulate salivary gland secretion. **Pilocarpine (B) does stimulate secretion from salivary glands, but it is a parasympathetic agonist, not an autocoid.

When using an EpiPen, the dosage for an adult will be metered in which milligram increments? A 300 mg B 30 mg C 0.3 mg D 0.15 mg E 15 mg

ANS: C The usual adult dosage of epinephrine is 0.3 mg (C). The dose for children is usually 0.15 mg (D). **Choices A, B, and E are far too high dosages to be safe.

A drug that has an effect on the fetal development is said to have a/an A side effect. B toxic effect. C therapeutic effect. D teratogenic effect. E idiosyncratic reaction.

ANS: D A drug that causes an adverse reaction in the developing fetus is termed teratogenic effect (D). **The FDA has ranked drugs into five pregnancy categories: A, B, C, D, and X, ranked from least risky to most risky. A side effect (A) is a dose-related reaction that is not part of the desired therapeutic effect. A toxic effect (B) is an extension of the pharmacologic effect resulting from the drug's excessive and harmful effect on the target organ. The therapeutic effect (C) is the desired drug effect on target organs. An idiosyncratic effect or reaction (E) is a genetically related abnormal drug response that is atypical compared with that in the general population.

Which major neurotransmitter in autonomic ganglia leads to a rapid excitatory postsynaptic potential? A Dopamine B Epinephrine C Norepinephrine D Acetylcholine E Serotonin

ANS: D Acetylcholine (D) is the major neurotransmitter in ganglia and carries the stimulatory message from the preganglionic neuron to the postganglionic neuron. Acting on nicotinic cholinergic receptors linked to sodium channels, acetylcholine causes a rapid excitatory postsynaptic potential. **Dopamine (A), norepinephrine (C), or both are released from interneurons in sympathetic ganglia, but they cause an inhibitory postsynaptic potential. **Epinephrine (B) plays no major role in preganglionic transmission. **Serotonin (E) may have a minor role in neurotransmission in some ganglia, but only in a delayed response in the postganglionic neurons.

Extrapyramidal adverse effects caused by phenothiazine antipsychotic drugs A can be treated with anticholinergic drugs. B affect muscle control (dystonic reactions). C include akathisia. D A, B, and C E A and B only

ANS: D D is the correct choice, as options A, B, and C are all correct. **Anticholinergic drugs (A) such as benztropine (Cogentin) and trihexyphenidyl (Artane) can treat these side effects. **Dystonic reactions (B) and akathisia (C) are types of extrapyramidal effects. **Answer (E) does not include all of the correct possibilities.

Which drug most effectively blocks the itching, pain, and swelling from histamine released in the skin? A Chlorthalidone (Hygroton) B Doxazosin (Cardura) C Candesartan (Atacand) D Diphenhydramine (Benadryl) E Isoproterenol (Isuprel)

ANS: D Diphenhydramine (Benadryl) (D) is an antihistamine that blocks histamine H1 receptors and inhibits the above effects of histamine on nerves and blood vessels. **Chlorthalidone (Hygroton) (A) is a thiazide type diuretic. **Doxazosin (Cardura) (B) is an alpha 1-adrenergic receptor blocker. **Candesartan (Atacand) (C) is an angiotensin II receptor blocker. **Isoproterenol (Isuprel) (E) is a nonselective beta adrenergic receptor agonist. These drugs are typically used in the treatment of hypertension but have no or minimal effects on acute responses to histamine because they do not block histamine receptors or alleviate acute inflammation.

Patients taking metronidazole hydrochloride (HCl) (Flagyl) should be advised to avoid which substance? A Milk B Antacids C Grapefruit juice D Mouth rinses with alcohol

ANS: D Ingestion of metronidazole HCl (Flagyl) (D) with alcohol may result in a disulfiram (Antabuse)-like reaction. Symptoms include nausea, abdominal cramps, flushing, vomiting, or headache. **Milk (A), antacids (B), and grapefruit juice (C) will not cause this interaction with metronidazole.

Which is the shortest-acting barbiturate? A Pentobarbital (Nembutal) B Phenobarbital (Luminal) C Mephobarbital (Mebaral) D Methohexital (Brevital)

ANS: D Methohexital (Brevital) (D) is an ultra-short-acting barbiturate. **Pentobarbital (Nembutal) (A) is a short-acting barbiturate. *Phenobarbital (Luminal) (B) and mephobarbital (Mebaral) (C) are long-acting barbiturates.

Which drug inhibits renin release from the kidneys? A Candesartan (Atacand) B Digoxin (Lanoxin) C Enalapril (Vasotec) D Metoprolol (Lopressor) E Nifedipine (Procardia)

ANS: D Metoprolol (Lopressor) (D), blocks beta 1-adrenergic receptors in the juxtaglomerular cells of the kidney's afferent arterioles, inhibiting the release of renin. Renin catalyzes the conversion of angiotensinogen to angiotensin I, which causes vasoconstriction, and stimulates aldosterone release. Aldosterone promotes sodium retention in the kidney, further raising blood pressure by vasoconstriction. Blocking the renin-angiotensin pathway reduces blood pressure and the demand on the heart, making this class of drugs important in the treatment of hypertension and heart failure. **Candesartan (Atacand) (A) and enalapril (Vasotec) (C) also inhibit this pathway but do so "downstream" from renin release: Enalapril inhibits angiotensin receptor-enzyme (ACE); and candesartan blocks the angiotensin II receptor. **Digoxin (Lanoxin) (B) stimulates the heart directly, increasing its force of contraction. It does so by inhibiting the sodium- potassium pump (Na+,K+-adenosine triphosphatase [ATPase]) in the plasma membranes of cardiac cells. **Nifedipine (Procardia) (E) is a calcium channel blocker, which reduces the contraction of cardiac muscle and increases vasodilation of the arteries—two methods of reducing blood pressure. This action is not linked to renin release.

Which of the following drugs is the BEST choice for treating an opioid overdose? A Flumazenil (Romazicon) B Prochlorperazine (Compazine) C Diphenhydramine (Benadryl) D Naloxone (Narcan)

ANS: D Naloxone (Narcan) (D), an opioid receptor antagonist, reverses the actions of other opioids. **Flumazenil (Romazicon) (A), a benzodiazepine receptor antagonist, may not have any impact on the opioid overdose. **Prochlorperazine (Compazine) (B) is one of a class of antipsychotic medications prescribed for treatment of nausea and vomiting and may exacerbate the symptoms of opioid overdose. **Intravenous diphenhydramine (Benadryl) (C) is an antihistamine that may reverse some of the actions of the overdose, but it is not the best drug choice.

Each of the following agents has good absorption through the gastrointestinal (GI) tract EXCEPT one. Which one is the EXCEPTION? A Itraconazole (Sporanox) B Griseofulvin (Fulvicin P/G, Grisactin Ultra) C Terbinafine (Lamisil) D Nystatin (Mycostatin, Nilstat)

ANS: D Nystatin (Mycostatin, Nilstat) (D), when taken orally, is not absorbed but is excreted unchanged in feces. **Itraconazole (Sporanox) (A), griseofulvin (Fulvicin P/G, Grisactin Ultra) (B), and terbinafine (Fulvicin P/G, Grisactin Ultra) (C) all have good oral absorption.

All of the following are characteristics of xylitol EXCEPT one. Which one is the EXCEPTION? A It inhibits the attachment of biofilm to teeth. B It prevents the transmission of oral bacteria from mother to child. C It reduces the levels of Streptococcus mutans in saliva and plaque. D It is bactericidal to Streptococcus mutans in saliva and plaque.

ANS: D The mechanism of xylitol's anti-caries action is bacteriostatic (D), not bactericidal (D). The main strains of S. mutans and S. sanguis cannot metabolize xylitol, and this effect is potentiated with the addition of sorbitol. Xylitol has been found to inhibit the attachment of biofilm

The patient has recently been prescribed a drug by a neurologist to treat a painful jaw. The pain was sharp and intermittent and seemed to be triggered by the slightest touch. The patient could not remember the name of the disorder, but it was explained to the patient that the prescribed "pain killer" was an antiepileptic drug used for this type of pain. Which would be the most likely drug prescribed? A Oxycodone (in Percodan, Percocet) B Dihydrocodeine (in Synalgos DC) C Celecoxib (Celebrex) D Carbamazepine (Tegretol) E Acetaminophen (Tylenol)

ANS: D The pain described is consistent with trigeminal neuralgia (tic douloureux) because of the type of pain, the location of the pain involving cranial nerve V, and the fact that a neurologist made the diagnosis. Carbamazepine (Tegretol) (D) is a drug commonly used to treat trigeminal neuralgia. It is effective in inhibiting nerve conduction by blocking neuronal sodium channels, and this also makes it useful to treat certain types of seizure disorders. **Oxycodone (Percodan, Percocet) (A) and dihydrocodeine (Synalgos DC) (B) are both opioids and are useful in treating pain but are less effective in treating the neuropathic type pain described here. **Celecoxib (Celebrex) (C) is a cyclooxygenase-2 (COX-2) inhibitor and is used as an anti-inflammatory and analgesic agent. **Acetaminophen (Tylenol) (E) is not particularly effective in treating neuropathic pain.

In addition to treatment of tonic-clonic and partial seizure disorders, carbamazepine (Tegretol) is also used in the treatment of A trigeminal neuralgia. B Parkinson disease. C chronic pain syndromes. D A, B, and D. E A and C only.

ANS: E Carbamazepine (Tegretol) is used in the treatment of trigeminal neuralgia (A) and other chronic pain syndromes (C) in addition to some seizure disorders (E). Parkinson disease (B) is treated with dopamine agonists and anticholinergics, but carbamazepine is not used in its treatment. Choice D does not contain the correct components.

A patient who has asthma and has been taking oral theophylline (Theolair) for several months develops an acute infection in the oral cavity. Since the patient reports an allergy to penicillin, oral erythromycin ethylsuccinate (E.E.S.), at a dose of 400 mg four times a day, is prescribed. Two days later, the patient begins to feel ill, reporting dizziness, nervousness, confusion, nausea and vomiting, and rapid heart rate. Which is the most likely explanation for the patient's symptoms? A Erythromycin inhibited the renal excretion of theophylline. B Erythromycin enhanced the gastric absorption of theophylline. C Theophylline increased the affinity of erythromycin at the site of action. D Theophylline decreased the excretion of erythromycin. E Erythromycin inhibited the hepatic metabolism of theophylline.

ANS: E Erythromycin inhibits the liver enzymes (the cytochromes) needed to metabolize many drugs, including theophylline (E). The symptoms described are consistent with theophylline toxicity, which occurred when failure to metabolize theophylline caused the plasma levels to rise to harmful levels. **Erythromycin does not affect renal excretion of other drugs (A). **Erythromycin may cause severe gastrointestinal distress but does not enhance absorption of other drugs (B). **Theophylline does not affect cell affinity for erythromycin (C), or decrease its excretion (D). Because of the low therapeutic index of theophylline, another choice of antibiotic would be better.

Which analgesic drug reduces blood clotting for the longest period? A Ibuprofen (Motrin) B Naproxen (Aleve, Naprosyn) C Acetaminophen (Tylenol) D Codeine E Aspirin

ANS: E Only aspirin (E) irreversibly inhibits cyclooxygenase, which inhibits the synthesis of thromboxane A2, and inhibits platelet aggregation for the life of the platelet (7-10 days). **Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (A) and naproxen (B) may also affect blood clotting but do so only for a short time because they reversibly inhibit cyclooxygenase and inhibit the synthesis of thromboxane A2. **Acetaminophen (C) has a minor effect on blood clotting in most cases. Codeine (D) has no major effect on blood clotting mechanisms, including platelet aggregation.

Which drug is used as an antidepressant and is considered an SSRI? A Amitriptyline (Elavil) B Bupropion (Wellbutrin) C Haloperidol (Haldol) D Lithium carbonate (Eskalith) E Paroxetine (Paxil)

ANS: E Paroxetine (Paxil) (E) is an antidepressant that primarily blocks the reuptake of serotonin in the brain. **Amitriptyline (Elavil) (A), also an antidepressant, blocks both serotonin and norepinephrine reuptake mechanisms non-selectively. **The mechanism of bupropion (Wellbutrin) (B) is not as well understood, although reuptake of dopamine may play a role. **Haloperidol (Haldol) (C) is an antipsychotic drug that blocks the dopamine receptors. **Lithium (Eskalith) (D) is used in treatment of the manic phase of bipolar disease or manic-depressive illness.

The antipsychotic effect of thioridazine (Mellaril) is largely caused by which mechanism in the brain? A Blocking the reuptake of norepinephrine and serotonin B Blocking sodium channels in nerves C Blocking calcium channels in nerves D Enhancing the effect of gamma aminobutyric acid (GABA) on chloride channels E Blocking dopamine receptors on nerves

ANS: E Potencies of traditional antipsychotic drugs such as thioridazine are correlated with their affinities for D2 dopamine receptors (E). **Blocking the reuptake of norepinephrine and serotonin (A) is the mechanism of action of several antidepressants. **Blocking sodium channels in the central nervous system (CNS) (B) is a mechanism of action of several antiepileptic drugs such as phenytoin. **Blocking calcium channels in the CNS (C) is a characteristic of several antiepileptic drugs used in the treatment of absence (petit mal) seizures. **Most sedatives act by enhancing the effect of GABA (D), an inhibitory neurotransmitter, on chloride channels.

Which drug or drug class is most likely to result in bone loss when administered chronically in typical clinical doses? A Alendronate (Fosamax) B Ethinyl estradiol (Estinyl) C Conjugated estrogens (Premarin) D Raloxifene (Evista) E Prednisone (Deltasone)

ANS: E Prednisone (Deltasone) (E), as well as other glucocorticoid steroids, promotes a negative calcium balance by decreasing calcium absorption from the gastrointestinal (GI) tract. They also increase osteoclast activity and decrease osteoblast activity in bone and have other mechanisms as well. These effects may, and often do, lead to osteoporosis. **Alendronate (Fosamax) (A) is a bisphosphonate, and bisphosphonates bind to bone remodeling surfaces, reducing the number and activity of osteoclasts. This is useful in treating certain bone loss disorders such as osteoporosis and Paget disease. **Estrogens, including ethinyl estradiol (Estinyl) (B) and conjugated estrogens (Premarin) (C), increase osteoblast activity, which then suppresses the action of osteoclasts. **Raloxifene (Evista) (D) is a selective estrogen receptor modulator (SERM), which has a similar beneficial effect on bone. It is more selective than ethinyl estradiol or conjugated estrogens in its ability to stimulate estrogen receptors.

Which drug would be indicated in the treatment of methicillin-resistant Staphylococcus aureus (MRSA)? A Cephalexin (Keflex) B Clarithromycin (Biaxin) C Dicloxacillin (Dynapen) D Penicillin V (Pen-Vee-k) E Vancomycin (Vancocin)

ANS: E Vancomycin (Vancocin) (E) is the antibiotic indicated for the treatment of S. Aureus. It is active in the presence of penicillinases produced by S. aureus and other mechanisms of resistance to beta-lactams. **MRSA is largely resistant to clarithromycin (Biaxin) (B). **Dicloxacillin (Dynapen) (C) is very similar to methicillin and is ineffective against this infection. **Resistance by MRSA also extends to other beta-lactam antibiotics such as cephalexin (Keflex) (A) and penicillin V (Pen-Veek) (D).

Which drug reduces coagulation by inhibiting the activation (carboxylation) of certain clotting factors in the liver? A Aspirin B Alteplase (t-PA) (Activase) C Clopidogrel (Plavix) D Heparin E Warfarin (Coumadin)

ANS: E Warfarin (Coumadin) (E) competitively inhibits vitamin K epoxide reductase, acting as a vitamin K antagonist. This action leads to inhibition of carboxylation of prothrombin factors VII, IX, and X, as well as other factors leading to reduced coagulation capacity. **The other drugs listed act on elements in blood. Aspirin (A) and Clopidogrel (Plavix) (C) are inhibitors of platelet aggregation; aspirin, due to its effect on cyclooxygenase, inhibits the production of thromboxane A2, and Clopidogrel inhibits the effect of adenosine diphosphate on platelets. Alteplase (t-PA, Activase) (B) binds to fibrin and leads to the hydrolysis and breakup of fibrin. Heparin (D) reduces blood clotting by accelerating the activity of antithrombin III and by other mechanisms.