NURS 3305 Pharmacology Exam 1

10:30 pm =

2230 hours

Enteric coating

(EC) dissolves in intestine, so decreases stomach irritation; absorption variable

Prescribers

(MD, NP in most states, CNM, DO, DDS) defined by state practice acts additional in some states: psychologists

Dispensers

(MD, PharmD, and delegates) NOT RNs in any state Examples: night shift; rural hospital; office samples

Metabolism

(biotransformation): enzymatically mediated alteration of drug structure

Why should providers be careful of certain drug combinations?

- Both drugs may be extensively protein bound - Both drugs may compete for same metabolic pathways (enzyme system) - Both drugs may compete for pumps in tubules - Both drugs may simply have similar or opposing effects (multivitamin with vitamin K and heparin)

Drug effects can be

- unpredictable in the individual - may not always make the person "feel better" (examples: cancer drugs, anticonvulsants)

Narrow therapeutic range

-small difference between therapeutic and toxic levels (insulin) Toxicity can occur suddenly Monitor drug levels: peak and trough We obtain drug "peak and trough" levels right before we administer and then 1-2 hours after Monitor for side effects

Creatinine (Cr; assesses GFR) adult norms

0.6 - 1.3 mg/dL > 4mg/dL indicates serious renal impairment

12:16 am =

0016 hours

6:30 am =

0630 hours

How drugs cross cell membranes

1. Passive diffusion 2. Filtration or osmotic pressure gradient difference 3. Active transport 4. Facilitated diffusion 5. Pinocytosis

Elderly and Drugs

30% of all drugs are taken by the elderly Multiple health issues Many drugs are prescribed: "Polypharmacy" Adherence is big issue: cut tablets in half 90% underdose themselves Of these people, 75% is intentional underdosing So, 67% of all elderly underdose intentionally 40% fail to take as prescribed (timing, food)

It takes ______ half-lives to reach steady state

4.5

BUN/CR ratio should be

6-25, 15 is optimal

Syrup

A concentrated solution of sugar in water to which specific medicinal substances are usually added. Syrups usually do not represent a very high percentage of the active drug. Some syrups are used principally to give a pleasant odor and taste to solutions

Drug Class

A group of medications that may work in the same way, have a similar chemical structure, or are used to treat the same health condition.

Solution

A liquid containing a dissolved substance

Prodrug

A medication or compound that, after administration, is metabolized into a pharmacologically active drug. Inactive prodrugs are pharmacologically inactive medications that are metabolized into an active form within the body.

As a nurse or health care professional, what information might you want to research about drugs that you are taking? What resources may be helpful?

A number of drug references have been compiled expressly for nurses. All address topics of special interest to nurses, including information on administration, assessment, evaluation, and patient education. Representative nursing drug references include Saunders Nursing Drug Handbook and Mosby's Drug Guide for Nurses, both published annually.

Suppository

A semisolid substance for introduction into the rectum, vagina, or urethra, where it dissolves. It may be used to stimulate a bowel movement, but often serves as a vehicle for medicines to be absorbed. It is commonly shaped like a cylinder or cone and may be made of soap, glycerinated gelatin, or cocoa butter

Tablet

A small, disk-like mass of medicinal powder

Lozenge

A small, dry, medicinal solid to be held in the mouth until it dissolves

Extract

A solid or semisolid preparation made by removing the soluble portion of a compound by using water or alcohol as the solvent and evaporating the solution. The active principle of a drug obtained by distillation or chemical processes

Aerosol

A solution dispensed as a mist. Any suspension of particles in air or gas

Spirit

A solution of essential or volatile liquid. Any distilled volatile liquid

Capsule

A special container made of gelatin, sized for a single dose of a drug. The enclosure prevents the patient from tasting the drug

Medication

A substance used in treating disease or relieving pain

Ointment

A viscous, semisolid vehicle used to apply medicines to the skin. Ointments differ from creams or lotions in their superior ability to occlude the skin and improve the uptake of drugs. The base or vehicle of an ointment typically includes petrolatum, fats, oils, resins, or water-based or water-soluble compounds

Cream

A water-soluble medicinal preparation applied to the skin. An ointment differs from a cream in that it has an oil base, as opposed to being water-soluble

QT interval drugs

AKA QT drugs - refers to the ability of some medications to prolong the QT interval on the electrocardiogram, thereby creating a risk of serious dysrhythmias. The QT interval is a measure of the time required for the ventricles to repolarize after each contraction. When the QT interval is prolonged, patients can develop a dysrhythmia known as torsades de pointes, which can progress to potentially fatal ventricular fibrillations

Identify at least six drugs that should be avoided in the elderly:

ANALGESICS Indomethacin [Indocin]: Risk of GI bleeding, especially with long-term use; some may contribute to heart failure. Not effective at usual doses, risk of neurotoxicity, confusion, delirium. ANTIHISTAMINES (First generation) Diphenhydramine [Benadryl]: Anticholinergic effects: constipation, urinary retention, blurred vision ANTIHYPERTENSIVES, Alpha-Adrenergic Blocking Agents Alpha 1 blockers (eg, doxazosin [Cardura], prazosin [Minipress], terazosin [Hytrin]): High risk of orthostatic hypotension and falls; less dangerous drugs are available. SEDATIVE-HYPNOTICS Barbiturates: Physical dependence; compared with other hypnotics, higher risk of falls, confusion, cognitive impairment DRUGS FOR URGE INCONTINENCE Oxybutynin [Ditropan]: Urinary retention, confusion, hallucinations, sedation MUSCLE RELAXANTS Carisoprodol [Soma]: Anticholinergic effects, sedation, cognitive impairment; may not be effective at tolerable dosage

Efficacy

Ability of a drug to cause a certain response, regardless of the strength of that response Drugs are best compared as to their efficacy

Think onset

Absorption Movement from the site of administration into the bloodstream. All drug routes, except IV, involve passing through cell membranes

Pharmacokinetics and the elderly

Absorption (rate is slowed) Distribution (often less serum albumin [less protein binding]) Metabolism (decreased) Excretion (decreased) MOST CONCERNING OF ALL: KIDNEY FUNCTION IS DECREASED: CREATININE & BLOOD UREA NITROGEN (BUN) SHOULD BE ASSESSED REGULARLY Cell receptors (less) Cognitive changes (remembering) Psychosocial and economic Sensory organs Swallowing "Start slow go slow!"

Metabolism: Influences

Age (young and old yields different speeds and effectiveness of liver drug metabolism) "Enzyme induction" (caused by certain meds, nicotine) some drugs increase overall liver enzyme activity (phenobarbital) Remember: MOST metabolism acts to change drug so it is better excreted - if given with another drug, may need to increase the dose of the second drug - if given with a prodrug - may need to decrease the dose of the prodrug

SHOULD give - but often are not given in older adults

Aspirin (low-dose) Beta-blockers after MI ADEQUATE pain meds Immunizations: - Seasonal flu - Pneumococcal

Older children/Adolescents and Drugs

Assent is required Control is essential: it is a cooperative venture Not "small adults": low dosages Low acceptance of side effects (eg. Depo-provera) Developmental task?

IM injections

Assess for adequate muscle mass Length of needle is determined by size of muscle mass Proper needle length to ensure delivery into muscle Proper identification of site using landmarks  Do not aspirate insulin or heparin) Inject appropriate volumes Newborn: 0.5 cc Child: 1 cc Adult 3 cc Pediatric safety considerations (holding securely, firmly, and humanely)

Generic name

Assigned by the United States Adopted Names Council. Each drug has only one of these names. Also known as the nonproprietary name. Nonproprietary means it is not protected by trademark or patent or copyright

Intramuscular (IM)

Barriers to Absorption: Capillary wall (easy to pass) Absorption Pattern: Rapid with water-soluble drugs. Slow with poorly soluble drugs. Advantages: Permits use of poorly soluble drugs. Permits use of depot preparations. Disadvantages: Possible discomfort. Inconvenient. Potential for injury.

Oral (PO)

Barriers to Absorption: Epithelial lining of GI tract; capillary wall Absorption Pattern: Slow and variable Advantages: Easy. Convenient. Inexpensive. Ideal for self-medication. Potentially reversible, and hence safer than parenteral routes. Disadvantages: Variability. Inactivation of some drugs by gastric acid and digestive enzymes. Possible nausea and vomiting from local irritation. Patient must be conscious and cooperative.

Intravenous (IV)

Barriers to Absorption: None (absorption is bypassed) Absorption Pattern: Instantaneous Advantages: Rapid, onset, and hence ideal for emergencies. Precise control over drug labels. Permits use of large fluid volumes. Permits use of irritant drugs. Disadvantages: Irreversible. Expensive. Inconvenient. Difficult to do, and hence poorly suited for self-administration. Risk of fluid overload, infection, and embolism. Drug must be water-soluble.

Subcutaneous (subQ)

Barriers to Absorption: Same as IM Absorption Pattern: Same as IM Advantages: Same as IM Disadvantages: Same as IM

Can a generic drug always be substituted for a brand name drug?

Because all equivalent products - generic or brand name - contain the same dose of the same drug, the only real concern with generic formulations is their rate and extent of absorption. For a few drugs, a slight increase in absorption can result in toxicity, and a slight decrease can result in therapeutic failure. Hence, with agents for which a small difference in absorption can be important, decisions to stay with a brand name should be based on the evidence and made on a case-by-case basis. Generics and branded drugs most often differ in their non-active ingredients

Which person works in an inpatient setting, whose actions are not checked by anyone else?

Because the nurse is the last person who can catch mistakes made by others, and because no one is there to catch mistakes the nurse might make, the nurse bears a heavy responsibility for ensuring patient safety.

3 types of side effects

Beneficial (diphenhydramine [Benedryl]; sildenafil [Viagra]; "off-label" use) Adverse (undesired, uncomfortable, or dangerous) Toxic (amount of drug is too high, dangerous/deadly)

pH

Best absorption when the difference in pH between the drug molecules and cell membranes is minimal Acid drugs tend to be best absorbed in acid environments, such as the stomach. Aspirin ("ASA": salicylates) is maximally absorbed in acid stomach, but it is also the cause of many side effects If we give aspirin (an acid drug) with an antacid (an alkaline drug), this will change the environment to more alkaline and absorption will be decreased Base drugs tend to ionize in acid media; these drugs can be "enteric coated" so they do not dissolve until they hit the intestines, a more alkaline environment

Ability of the drug to reach the systemic circulation from its site of administration

Bioavailability Therefore, bioavailability is a function of absorption

What do you do if you make a medication error?

CHECK YOUR CLIENT Immediately Then, Notify: charge RN or supervisor; FACULTY prescriber Pharmacist client: as a student, you do this with mentoring Document event: what occurred , condition of client, who was notified, incident report Take steps to prevent - coworkers When you get home: write up all you can remember and keep Do not beat yourself up - learn from it

What do the following lactation risk categories mean: L5

CONTRAINDICATED: Studies in breastfeeding mothers have demonstrated that there is significant and documented risk to the infant based on human experience; or it is a medication that has a high risk of causing significant damage to an infant. The risk of using the drug in breastfeeding women clearly outweighs any possible benefit from breastfeeding. The drug is contraindicated in women who are breastfeeding an infant.

pH dependent ionization

Can be used to accelerate renal excretion of drugs. Recall that passive tubular reabsorption is limited to lipid-soluble compounds. Because ions are not lipid soluble, drugs that are ionized at the pH of tubular urine will remain in the tubule and be excreted. Consequently, by manipulating urinary pH in such a way as to promote the ionization of a drug, we can decrease passive reabsorption back into the blood, and can thereby hasten the drug's elimination. This principle has been employed to promote the excretion of poisons as well has medications that have been taken in toxic doses. The treatment of aspirin poisoning provides and example of how manipulation of urinary pH can be put to therapeutic advantage. When children have been exposed to toxic doses of aspirin, they can be treated, in part, by giving an agent that elevates urinary pH (ie, makes the urine more basic). Since aspirin is an acidic drug, and since acids tend to ionize in basic media, elevation of urinary pH causes more of the aspirin molecules in urine to become ionized. As a result, less drug is passively reabsorbed and hence more is excreted.

Sustained-Released Preparations

Capsules filled with tiny spheres that contain the actual drug; the individual spheres have coatings that dissolve at variable rates. Because some spheres dissolve more slowly than others, the drug is released steadily throughout the day. The primary advantage of these preparations is that they permit a reduction in the number of daily doses. These formulations have the additional advantage of producing relatively steady drug levels over an extended time (much like giving a drug by infusion). The major disadvantages of these formulations are high cost and the potential for variable absorption.

hair products, tobacco, herbicides

Carcinogenesis

Nasogastric Medications

Check tube placement (aspiration vs auscultation): you learn this in skills lab Keep head of bed elevated and clamp suction Liquids best If not, be sure you can crush Know: No hydrophillic gels, time released pills, capsules, or enteric coated tablets Flush tube before and after administration

Formulary Drugs

Company or agency identifies the "best value": cost mostly established as having some efficacy, but perhaps not the most efficacy. Even if on formulary, may be limited in the quantity dispensed and may need prior authorization (prescriber may need to call the insurance company and get permission). May change yearly May or may not be research or data-based. Non-formulary: self-pay or high co-pay or may simply NOT be available (hospitals/clinics).

Competition for active tubular transport

Competition between drugs for active transport can delay renal excretion, thereby prolonging effects. The active transport systems of the renal tubules can be envisioned as motor-driven revolving doors that carry drugs from the plasma into the renal tubules. These "revolving doors" can carry only a limited number of drug molecules per unit of time. Accordingly, if there are too many molecules present, some must wait their turn. Because of competition, if we administer two drugs at the same time, and if both use the same transport system, excretion of each will be delayed by the presence of the other. Competition for transport has been employed clinically to prolong the effects of drugs that normally undergo rapid renal excretion. For example, when administered alone, penicillin is rapidly cleared from the blood by active tubular transport. Excretion of penicillin can be delayed by concurrent administration of probenecid, an agent that is removed from the blood by the same tubular transport system that pumps penicillin. Hence, if a large dose of probenecid is administered, renal excretion of penicillin will be delayed while the transport system is occupied with moving the probenecid. Years ago, when penicillin was expensive to produce, combined used with probenecid was common. Today penicillin is cheap. As a result, rather than using probenecid to preserve penicillin levels, penicillin is simply given in larger doses.

Enteric-Coated Preparations

Consist of drugs that have been covered with a material designed to dissolve in the intestine but not the stomach. Materials used include fatty acids, waxes, and shellac. Because these preparations release their contents into the intestine and not the stomach, these preparations are employed for two general purposes: (1) to protect drugs from acid and pepsin in the stomach, and (2) to protect the stomach from drugs that can cause gastric discomfort. The primary disadvantage of these preparations is that absorption can be even more variable than with standard tablets. Because gastric emptying time can vary from minutes up to 12 hours, and because enteric-coated preparations cannot be absorbed until they leave the stomach, variations in gastric emptying time can alter time of onset. Furthermore, enteric coatings sometimes fail to dissolve, thereby allowing medication to pass through the GI trat without being absorbed at all.

L5

Contraindicated: Anti-cancer drugs, most controlled substances, Lithium

Drug Development:

Costly & Lengthy (often 10-12 years)

The more protein-bound a drug is

Decreases the amount of free drug in plasma (Example: warfarin 99% protein bound)

Right Drug

Different Drug forms -Inderal vs Inderal LA -Bactrim vs Bactrim DS -Cardiazem vs Cardiazem SR Check against the written prescription or order, not MAR, for optimal safety Similar Spelling - cephradine (Velosef) - cefuroxime (Ceftin) - cefotaxime (Cloforan) Similar sounding medications when taking a phone or verbal order "Ancef" vs "Aricept" Have prescriber spell it out "RB&V": read back and verify (and document that you did so) You must check for therapeutic and side effects for each drug Check for allergies for each drug component  Identify correct preparation

What should you do if, when mixing medications, a precipitation forms?

Discard the solution. But, not all drug incompatibilities form a noticeable precipitate. Most cloudy suspensions can not be administered IV: check!

Know what the specific measurable therapeutic outcome is for each drug

Diuretics - look for increased urine output Antihypertensive agents - lowered blood pressure Opioids and NSAIDS - subjective reports of pain relief

Beers List

Do NOT give: Demerol (meperidine) for pain Most muscle relaxants Most antianxiety meds (falls: hip fractures) Digoxin (cardiotonic) All antihistamines Many NSAIDs Long term (daily) laxatives

So, a highly protein-bound drug molecule

Does NOT cause drug effects unless given in large doses Cannot easily cross out of theblood stream to its site of action because: - Once bound to protein - simply too big of a molecule - Also, once protein-bound, it becomes ionized and cannot easily get across the capillary membrane, out of the blood system, and to its site of action

Not recommended site for IM injections

Dorsogluteal site may deposit drug into fat in overweight clients; hard to avoid sciatic nerve Not recommended

Potency

Dose of a drug needed to produce a response compared to the dose of another drug to produce the same response Two drugs produce same effect but at different doses, one is more potent

Dynamics:

Drug characteristics in the body (duration, etc) Drug interactionsEvaluating for therapeutic and side effects - Therapeutic effects - Side Effects - Beneficial effects - Adverse effects - Toxic effects The effects of the drug actions on the body

How commonly do pregnant women take medications?

Drug use during pregnancy is common: about two-thirds of pregnant patients take at least one medication, and the majority take more.

First pass effect

Drugs (eg, nitroglycerin) undergo extensive inactivation as they pass through the liver, a phenomenon known as the first-pass effect.

pH and ionization

Drugs and the environments they go into, BOTH have pH  Absorption is best when drug molecules have no charge (neutral).  If the environment that the drug is put into is strong acid or alkaline this may cause the drug to ionize and affect its absorption. Ionized molecules tends to bind more readily with proteins and have difficulty crossing cell membranes

Preparations altering absorption

Enteric coating Sustained released Transdermal patch IM depot preparations Solution

Do drugs cross the placenta?

Essentially all drugs can cross the placenta, although some cross more readily than others. The factors that determine drug passage across the membranes of the placenta are the same factors that determine drug passage across all other membranes. Accordingly, drugs that are lipid soluble cross the placenta easily, whereas drugs that are ionized, highly polar, or protein bound cross with difficulty. Nonetheless, for practical purposes, the clinician should assume that any drug taken during pregnancy will reach the fetus.

Most reliable drug references

FDA http://www.fda.gov/cder/index.html Pharmacist Drug Guides, if current Lexi-Comp Textbook Drug companies online

Oral Meds - Safety Hint

Facial asymmetry, drooling, pocketing of food may indicate that a patient has impaired ability to swallow. Liquids are the most difficult to swallow so aspiration is more likely. Thick liquid is safer to swallow than thin liquid (liquid Tylenol vs a tablet with water)

T/F: the trade name is not capitalized

False. The trade name is always capitalized

Protein binding

Free (unbound) circulating drug causes drug effects When drug molecules binds with proteins in the bloodstream, they become ionized  - decreases diffusion from blood through cell membrane into cell (drug molecule attached to protein is MUCH BIGGER) - Commonly binds with albumin Think about this: clients who have too much or too little albumin and drug effects: anorexics, elderly, newborns Reversible bonds

Pregnancy Risk Category C

Greater Risk Than B: Animal studies show a risk of fetal harm, but no controlled studies have been done in women. OR no studies have been done in women or animals.

Parental Routes of Medication Administration

Intravenous (IV) Intramuscular (IM) Subcutaneous (subQ)

"Therapeutic Index" (TI)

LD/50 / ED/50

Transdermal Medications

Long acting sustained-released drugs Will likely have systemic effects!

Common food drug interactions

MAO inhibitors and foods with tyrosine Tetracycline and calcium Grapefruit juice & simvastatin (Zocar)

What do the following lactation risk categories mean: L3

MODERATELY SAFE: There are no controlled studies in breastfeeding women, however the risk of untoward effects to a breastfed infant is possible; or controlled studies show only minimal non-threatening adverse effects. Drugs should be given only if the potential benefit justifies the potential risk to the infant.

Orphan drugs

Many are drugs for rare diseases, so there is little demand for them. Not necessarily experimental; many have been around for a long time. Students often do give them, but may need to get information from pharmacist

Middle Adults and Drugs

Many hormonal changes Cognitive skills falter due to stress & multiple responsibilities May not notice ADE or take the time to report them.  Self-medicate (OTC, alcohol) higher than all other age groups

Decreased absorption (food interactions)

May decreases rate and extent Calcium and tetracycline Digoxin and high-fiber (common)

Medication Reconciliation

Mechanisms/documentation at each site of care Joint Commission requirement Requires strict evaluation at each transfer of care for needs to hold/delete/change in order Identifying which drugs are being taken routinely Which are continued at new site Which are discontinued at new site

Transdermal Patches

Medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream. Often, this promotes healing to an injured area of the body. An advantage of this drug delivery route over other types of medication delivery such as oral, topical, intravenous, intramuscular, etc. is that the patch provides a controlled release of the medication into the patient, usually through either a porous membrane covering a reservoir of medication or through body heat melting thin layers of medication embedded in the adhesive. The main disadvantage to these delivery systems stems from the fact that the skin is a very effective barrier; as a result, only medications whose molecules are small enough to penetrate the skin can be delivered by this method.

Right Routes

Medication is given by the prescribed route only  Route is appropriate for the patient  KNOW: Change in route must be ordered by authorized prescriber A change in route OFTEN requires a change in dosage and/or frequency

L3

Moderately safe, no studies in lactation

Active transport

Molecules move across pressure gradients by use of certain proteins that pump the molecule across.  Uses cellular energy

Disadvantages of parenteral route

More expensive, requiring technical skill and $ Aseptic technique required Tissue damage possible Rapid onset, difficult to retrieve drug

Young Children and Drugs

Most dosages are weight-dependent: Example: Iron (ferrous sulfate) 4 mg/kg/day for infants Taste, smell, consistency is important Knowing how much was really taken (spitting, spilling) Eliciting cooperation Giving appropriate choices (examples: yours) Parents: pros and cons

Drugs can do one or more

Move through membranes to get into bloodstream  Travel through blood vessel cell membranes, getting out of the plasma, to reach the sites of action  Target the cell membranes as the site of action

Pharmacokinetics

Movement of a drug through the body & How the body affects drug actions  Absorption Distribution Metabolism Excretion

Allergic Response

Must know list of allergies BEFORE giving any drugsIf unresponsive, check wrist/neck or wallet to identify high risk medication conditions or medication usage Check for adverse effects AFTER admin as well When do we check after admin? Depends on route, dosage, and onset

marijuana (?), LSD, antineoplastics

Mutagenesis

Drugs with short half-lives

Need to be given more frequently

To improve adherence in older adults

Need to have elderly or their family keep a list of meds Bring in bottles (not only list) if going into urgent care  Include family in all teaching (meds and care) Assess for probability of non-adherence (cognition, cost, values, capability [hands/swallowing]), perception of value of drug As simple a regimen as possible (least number of pills, least times a day) Right preparation for their needs (liquid, or topical or suppository if difficulty with swallowing) Explaining the plan, writing down the plan, and evaluating if they get the plan; effective follow-up

Lactation

No barrier exists Little testing Cumulative effects are common Similar adverse effects as the mother (eg. ampicillin) Drug levels on newborn not well established Premature newborns: have to evaluate carefully - use of lactation consultant, pharmacist, and databases Not a "cookbook" solution Consider: - gestational age - age post-delivery - health status - weight - alternatives

Is there such thing as IV absorption?

No. Since IV medications are deposited rapidly into the circulation, it is essential to give it over the recommended time to prevent serious (& possibly lethal) side effects.

Is the intensity of an allergic reaction related to the drug dose?

No. The intensity of an allergic reaction is determined primarily by the degree of sensitization of the immune system, not by drug dosage. Put another way, the intensity of allergic reactions is largely independent of dosage. As a result, a dose that elicits a very strong reaction in one allergic patient may elicit a very mild reaction in another. Furthermore, since a patient's sensitivity to a drug can change over time, a dose that elicits a mild reaction early in treatment may produce an intense reaction later on.

Generics and branded drugs most often differ in their ________________ ingredients

Non-active Most of the time this is okay, but there are some classic cases in which this can be hazardous Ex. Theophylline and synthetic thyroid

Is the placebo effect bad or good? How can an RN use this information?

Not all placebo responses are beneficial; placebo responses can also be negative. If a patient believes that a medication is going to be effective, then placebo responses are likely to help promote recovery. Conversely, if a patient is convinced that a particular medication is ineffective or perhaps even harmful, then placebo effects are likely to detract from his or her progress. Because the placebo effect depends on the patient's attitude toward the medicine, fostering a positive attitude may help promote beneficial effects. In this regard, it is desirable that all members of the healthcare team present the patient an optimistic (but realistic) assessment of the effects that therapy is likely to produce.

What is the most common drug error that leads to a client death?

Of the human factors that can cause errors, performance deficits (eg, administering a drug IV instead of IM) are the most common (29.8%)

Elimination

Once drug is stopped, 94% of drug is excreted in 4.5 half lives

Distribution

Once drug molecules are absorbed into the blood system, they will then leave the blood system and cross capillary membranes to reach the sites of action Usually simple diffusion How well a drug is distributed is related to: -Local blood flow -Plasma protein binding -Special "barriers": Blood-brain & Placenta

Enteral Routes of Medication Administration

Oral (PO)

How are the following pharmacokinetic components altered when drugs are given to neonates: Absorption

Oral Administration: Gastrointestinal physiology in the infant is very different from that in the adult. As a result, drug absorption may be enhanced or impeded, depending on the physiochemical properties of the drug involved. Gastric emptying time is both prolonged and irregular in early infancy, and then gradually reaches adult values by 6 to 8 months. For drugs that are absorbed primarily from the stomach, delayed gastric emptying enhances absorption. On the other hand, for drugs that are absorbed primarily from the intestine, absorption is delayed. Because gastric emptying time is irregular, the precise impact on absorption is not predictable. Gastric acidity is very low 24 hours after birth and does not reach adult values for 2 years. Because of low acidity, absorption of acid-labile drugs is increased. Intramuscular Administration: Drug absorption following IM injection in the neonate is slow and erratic. Delayed absorption is due in part to low blood flow through muscle during the first days of postnatal life. By early infancy, absorption of IM drugs becomes more rapid than in neonates and adults. Transdermal Absorption: Drug absorption through the skin is more rapid and complete in infants than in older children and adults. The stratum corneum of the infant's skin is very thin, and blood flow to the skin is greater in infants than in older patients. Because of this enhanced absorption, infants are at increased risk of toxicity from topical drugs.

First Pass: Involves the _____ route

PO We swallow a pill absorbed in the stomach and small intestine then goes first into the portal circulation (hey...the liver, right?) then goes into arterial system to travel to the sites of action.

What do the following lactation risk categories mean: L4

POSSIBLY HAZARDOUS: There is positive evidence of risk to a breastfed infant or to breastmilk production, but the benefits from use in breastfeeding mothers may be acceptable despite the risk to the infant (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).

What is needed on medication orders?

Patient name Date Signed in ink or electronic Drug name Dosage (in milligrams/units, not volume) - Examples... Route Frequency

What needs to be on medication orders?

Patient name Date Signed in ink or electronic Drug name Dosage (in milligrams/units, not volume) Route Frequency

Vesicant

Peripheral IV drug destroys tissues if infiltrates

Physical effects of drugs on the body related to dosage and time

Pharmacodynamics

Causes of Adverse Effects

Pharmacologic Factors (CNS depressant -- all systems are dampened ) Client Factors (Age, smoking, alcohol, nutrition factors, obesity. Genetics, pre-existing disease, other drugs; self-administration behaviors -under-dosing, meals, mixing it wrongly) "Iatrogenic" factors :Human (individual or systems) error: 6 rights; Machine errors Wrong Diagnosis

Conditional Approval of New Drug Application (NDA) occurs after what phase of drug testing?

Phase III

Pharmacodynamics

Physical effects of drugs on the body related to dosage and time These concepts relate strongly to drug safety. Key concepts: - Receptor theory - Therapeutic range - Measuring blood levels of drugs - Therapeutic Index - Drug incompatibility - Drug interactions: Giving multiple drugs - Drug effects

Not a good barrier at all

Placenta RNs teach: "What gets into you, gets into the baby" (the placenta is not protective) The exception: insulin (cannot cross placenta) Ditto with breastmilk (mammary) glands: most drugs pass into milk

L4

Possibly harmful, need benefit/risk assessment

Phase IV

Post-marketing surveillance

Right Dose

Potential for Error Mathematical error in calculation of dosage  Medication not given in the dose ordered Dose ordered is not appropriate for patient Pharmacy dispenses wrong dose (rare) Dosage is not transcribed correctly (common)

no documented risk (riboflavin, vitamin B2)

Pregnancy category A

no documented risk in animals, and no testing done in pregnant women (ampicillin)

Pregnancy category B

adverse effects on animal fetuses, no adequate studies in pregnant women; benefit may outweigh risk (heparin)

Pregnancy category C

adverse effects seen in human fetuses; benefit may outweigh risk (lithium; many anticonvulsants)

Pregnancy category D

fetal risk in human fetuses - risks clearly outweigh benefits (estrogen, anti-cholesterol drugs )

Pregnancy category X

Inhaled Medications

Proper technique is essential May be quick acting, but many are sustained released preparations Clients are often prescribed multiple types: confusion Know which is for emergency treatment May have systemic effects!

Right Patient

Properly identify patient prior to medication administration Check name band & medical number even if this is your only client Ask patient their name & birth date & compare to band As a nursing student, you will be considered unsafe to practice if you do not check id band Verbally ask name Caution: NOT in reverse Locate clients with the same or similar names in rooms away from each other, never in the same room. When the agency has 2 clients with similar names, clearly follow "name alert" policy

How are the following pharmacokinetic components altered when drugs are given to neonates: Distribution

Protein Binding: Binding of drugs to albumin and other plasma proteins is limited in the infant, because (1) the amount of serum albumin is relatively low and (2) endogenous compounds (eg, fatty acids, bilirubin) compete with drugs for available binding sites. Consequently, drugs that ordinarily undergo extensive protein binding in adults undergo much less binding in infants. As a result, the concentration of free levels of such drugs is relatively high in the infant, thereby intensifying effects. To ensure that effects are not too intense, dosage in infants should be reduced. Protein-binding capacity reaches adult values within 10 to 12 months. Blood-Brain Barrier: The blood-brain barrier is not fully developed at birth. As a result, drugs and other chemicals have relatively easy access to the CNS, making the infant especially sensitive to drugs that affect CNS function. Accordingly, all medicines employed for their CNS effects (eg, morphine, phenobarbital) should be given in reduced dosage. Dosage should also be reduced for drugs used for actions outside the CNS if those drugs are capable of producing CNS toxicity as a side effect.

Pregnancy Risk Category X

Proven Risk of Fetal Harm: Studies in women of animals show definite risk of fetal abnormality. OR adverse reaction reports indicate evidence of fetal risk. The risks clearly outweigh any possible benefit. A statement on risk will appear in the "CONTRAINDICATION" section of drug labeling.

Pregnancy Risk Category D

Proven Risk of Fetal Harm: Studies in women show proof of fetal damage, but the potential benefits of use during pregnancy may be acceptable despite the risks (eg, treatment of life-threatening disease for which safer drugs re ineffective). A statement on risk will appear in the "WARNINGS" section of drug labeling.

5 factors affect absorption

Rate of dissolution Blood flow Surface area Lipid solubility pH or ionization

Pregnancy Risk Category A

Remote Risk of Fetal Harm: Controlled studies in women have been done and have failed to demonstrate a risk of fetal harm during the first trimester, and there is no evidence of risk in later trimesters.

How are the following pharmacokinetic components altered when drugs are given to neonates:

Renal drug excretion is significantly reduced at birth. Renal blood flow, glomerular filtration, and active tubular secretion are all low during infancy. Because the drug-excreting capacity of infants is limited, drugs that are eliminated primarily by renal excretion must be given in reduced dosage and/or at longer dosing intervals. Adult levels of renal function are achieved by 1 year.

"Over the counter" (OTC) and "Behind the counter" Drugs

Represent 60% of all drugs taken Most illnesses (60-90%) are treated first with OTC drugs Mean # of OTC drugs in American medicine cabinets is 24 (FDA, 2013) Significant factor in drug-drug interactions Illiteracy in America: 1 in 5 cannot read and understand a bottle of aspirin (Doak & Doak, 2010).

Six Rights of Medication Administration

Right Drug Right Client Right Dosage Right Time Right Route (Proper Documentation)

Can anyone "COVER YOU" if you are licensed

Risk & accountability falls to those who delegate (RNs) NO ONE CAN "COVER YOU" if you are licensed

What do the following lactation risk categories mean: L2

SAFER: Drugs which have been studied in a limited number of breastfeeding women without an increase in adverse effects in the infant; and/or the evidence of a demonstrated risk which is likely to follow use of this medication in a breastfeeding woman is remote.

What do the following lactation risk categories mean: L1

SAFEST: Drugs which have been taken by a large number of breastfeeding mothers without any observed increase in adverse effects in the infant. Controlled studies in breastfeeding women fail to demonstrate a risk to the infant and the possibility of harm to the breastfeeding infant is remote.

Parenteral Medications fastest to slowest

SC, IM, ID, IV drip, Piggyback, IV push, PCA

IM depot preparations

SLOWS Fluphenazine (Prolixin; antipsychotic) Medroxyprogesterone (DepoProvera) birth control 3 month-long IM Penicillin G & procaine (Wycillin) antibiotic and local anesthetic

L2

Safer, chances of harm are remote

L1

Safest, been studied with lactating women, no problems seen

To identify actual drug levels we draw blood for:

Serum drug level Peak and trough Trough: immediately prior to next dose Peak: when drug peaks - often 1-2 hours later

P450 enzyme systems

Six of the enzymes in this group are responsible for 90% of human drug oxidation The P450 enzymes are also responsible for many of the drug-drug interactions that occur  Drug-drug interactions cause serious complications to a patient's health. Common drugs with this concern: diazepam (Valium), anticonvulsants, SSRIs

Pregnancy Risk Category B

Slightly More Risk Than A: Animal studies show no fetal risk, but controlled studies have no been done in women. OR animal studies do show a risk of fetal harm, but controlled studies in women have failed to demonstrate a risk during the first trimester, and there is no evidence of risk in later trimesters.

When using ED50 as a starting dose

Some clients will always be under-treated and others overdosed

What should you do when you are interrupted preparing medications?

Start all over again!

Phase I

Subjects: healthy volunteers Tests: metabolism, pharmacokinetics, and biologic effects

Phase III

Subjects: patients Tests: safety and effectiveness

Phase II

Subjects: patients Tests: therapeutic utility and dosage range

Schedule II/IIN Controlled Substances (2/2N)

Substances in this schedule have a high potential for abuse, which may lead to severe psychological or physical dependence. Examples of Schedule ____ narcotics include: hydromorphone (Dilaudid®), methadone (Dolophine®), meperidine (Demerol®), oxycodone (OxyContin®, Percocet®), and fentanyl (Sublimaze®, Duragesic®). Other Schedule II narcotics include: morphine, opium, codeine, and hydrocodone. Examples of Schedule ____ stimulants include: amphetamine (Dexedrine®, Adderall®), methamphetamine (Desoxyn®), and methylphenidate (Ritalin®). Other Schedule ___ substances include: amobarbital, glutethimide, and pentobarbital.

Schedule IV Controlled Substances

Substances in this schedule have a low potential for abuse relative to substances in Schedule III. Examples of Schedule ____ substances include: alprazolam (Xanax®), carisoprodol (Soma®), clonazepam (Klonopin®), clorazepate (Tranxene®), diazepam (Valium®), lorazepam (Ativan®), midazolam (Versed®), temazepam (Restoril®), and triazolam (Halcion®).

Schedule V Controlled Substances

Substances in this schedule have a low potential for abuse relative to substances listed in Schedule IV and consist primarily of preparations containing limited quantities of certain narcotics. Examples of Schedule ___ substances include: cough preparations containing not more than 200 milligrams of codeine per 100 milliliters or per 100 grams (Robitussin AC®, Phenergan with Codeine®), and ezogabine.

Schedule III/IIIN Controlled Substances (3/3N)

Substances in this schedule have a potential for abuse less than substances in Schedules I or II and abuse may lead to moderate or low physical dependence or high psychological dependence. Examples of Schedule ____ narcotics include: products containing not more than 90 milligrams of codeine per dosage unit (Tylenol with Codeine®), and buprenorphine (Suboxone®). Examples of Schedule ______ non-narcotics include: benzphetamine (Didrex®), phendimetrazine, ketamine, and anabolic steroids such as Depo®-Testosterone

Schedule I Controlled Substances

Substances in this schedule have no currently accepted medical use in the United States, a lack of accepted safety for use under medical supervision, and a high potential for abuse. Some examples are heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), peyote, methaqualone, and 3,4-methylenedioxymethamphetamine ("Ecstasy").

Narrow margin of safety

TI = LD/50 divided by ED/50 Regular Insulin, Client A LD 30 Units ED 20 Units

Drugs with long half-life

Take longer to become therapeutic (antidepressants) Are given less frequently Take longer to be eliminated from body

How to administer transdermal medications

Take old patch off before putting new one on Apply on non-hairy areas Not over scar tissue Check skin for irritation

accutane, thalidomide

Teratogenesis

What is the Beers list?

The Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, commonly called the Beers List, is a guideline for healthcare professionals to help improve the safety of prescribing medications for older adults

Which of the 4 parts of pharmacokinetics is most affected by being elderly?

The aging process can affect all phases of pharmacokinetics. From early adulthood on, there is a gradual, progressive decline in organ function. This decline can alter the absorption, distribution, metabolism, and excretion of drugs. As a rule, these pharmacokinetic changes increase drug sensitivity (largely from reduced hepatic and renal drug elimination) Drug accumulation secondary to reduced renal excretion is the most important cause of adverse drug reactions in older adults.

Blood flow

The better the blood flow available to the drug, better the absorption. GI tract (mouth, intestines, rectum) & skin: highly vascular, so these are good routes by which to take drugs that we want to absorb well. Speed of the drug molecules passing close to the blood stream will affect absorption (very fast - little absorption; very slow - heavy absorption)

Liver disease and pharmacokinetics

The capacity of the liver to metabolise drugs depends on hepatic blood flow and liver enzyme activity, both of which can be affected by liver disease. In addition, liver failure can influence the binding of a drug to plasma proteins. These changes can occur alone or in combination; when they coexist their effect on drug kinetics is synergistic, not simply additive. The kinetics of drugs with a low hepatic extraction are sensitive to hepatic failure rather than to liver blood flow changes, but drugs having a significant first-pass effect are sensitive to alterations in hepatic blood flow.

What is the "placebo effect"?

The component of a drug response that is caused by psychological factors and not by the biochemical or physiologic properties of the drug. Although it is impossible to assess with precision the contribution that psychological factors make to the overall response to any particular drug, it is widely believed that, with practically all medications, some fraction of the total response results from a placebo effect. Although placebo effects are responses to the inactive placebo, the presence of a placebo response does not imply that a patient's original pathology was "all in the head."

How are the following pharmacokinetic components altered when drugs are given to neonates: Metabolism

The drug-metabolizing capacity of newborns is low. As a result, neonates are especially sensitive to drugs that are eliminated primarily by hepatic metabolism. When these drugs are used, dosages must be reduced. The capacity of the liver to metabolize many drugs increases rapidly about 1 month after birth, and approaches adult levels a few months later. Complete maturation of the liver develops by 1 year.

Peak

The highest concentrations of a drug in plasma.

Pre-term, low birth weight infant and pharmacokinetics

The kidneys of newborns are not fully developed. Until their kidneys reach full capacity (a few months after birth), infants have limited capacity to excrete drugs. This must be accounted for when medicating an infant. This condition will increase the risk for toxicity.

Trough

The lowest concentrations of a drug in plasma Measurement of peak and trough drug levels are used to determine whether an intravenously administered medication is consistently within therapeutic range. The trough is drawn just before a drug is scheduled to be given; the peak is drawn after the drug is administered (30 to 60 min after infusion). These measurements may guide therapy in the use of potentially toxic medications, e.g., aminoglycosides, which can have serious adverse effects if therapeutic levels are exceeded or can fail to work effectively if adequate drug levels are not attained.

Therapeutic effect

The objective of drug therapy is to provide maximum benefit with minimal harm.

Therapeutic range

The range of plasma drug levels, falling between the MEC (minimum effective concentration) and the toxic concentration. When plasma levels are within the therapeutic range, there is enough drug present to produce therapeutic responses but not so much that toxicity results. The objective of drug dosing is to maintain plasma drug levels within the therapeutic range.

Suspension

The state of a solid when its particles are mixed with, but not dissolved in, a fluid or another solid; also a substance in this state

The objective of drug therapy is to provide maximum benefit with minimal harm. Therapeutic range, also called therapeutic index is the concentration in the body at which the drug performs the desired action without becoming toxic.

Therapeutic effects

plasma level that produces therapeutic effects but not toxic effects.

Therapeutic range

Preclinical Testing (in animals)

Toxicity, pharmacokinetics, possible useful effects → Investigational New Drug (IND) Status

T/F: drugs have only a degree of selectivity: no completely selective drug

True

T/F: no such thing as a totally safe drug

True

T/F: DO NOT crush any time-released or enteric coated medications

True, you should never crush any time-released or enteric coated meds

What does grapefruit juice inhibit?

Two of the six major P450 enzymes These interactions can be deadly, and are largely preventable. Think: What will happen with most drugs if we INHIBIT metabolism? More than 100 drugs are metabolized by just one of the P450 enzymes, so any agent (such as grapefruit juice) that would inhibit this enzyme (3A4) has the potential to elevate serum levels of those drugs. This leads to toxicity

Agonist

Type of receptor affinity and efficacy (produces a desired effect)

Antagonist

Type of receptor affinity but NOT efficacy (naloxone, Narcan): key fits lock but does not open door; blocks the receptor site Binding is usually reversible

What is the "dilemma" of giving drugs to pregnant women?

Unfortunately, most drugs have no been tested during pregnancy. As a result, the risks for most drugs are unknown - hence the dilemma: The prescriber is obliged to balance risks versus benefits, without knowing what the risks really are.

Suppository

Vaginal, cervical, rectal Must have direct contact with mucosa (stool will interfere with rectal meds) May have significant side effects (systematic effects) Gloves, water-based lubricant, and light source are needed for administration

What is a "read-back" system for verbal orders?

Verbal orders given to pharmacists or medical staff are transcribed and then read back to the prescriber

Drug Regulation & Testing

Virtually unregulated until 1938, when the FDA was founded. After the thalidomide tragedy (primarily Europe) in 1962, regulation was strengthened: effectiveness and safety are now required aspects for drug approval in U.S. Still, however, there islittle testing throughoutthe lifespan.

Ear Medications

WASH HANDS Warm solution Tug pinna to straighten ear canal Adults: up and out Children: back and down Instill while client is positioned LAYING on side After: patient lies on side for 30-60 seconds Can massage below/behind ear to increase spread of medication

Eye Medications

WASH HANDS First The patient should lean the head back and look up. Lying down is best if someone else is applying the medication. A clean forefinger is used to gently pull the lower lid down to create a pocket, as shown. Eye drops are then dropped into the pocket, not directly onto the eye. Ointment is applied in a small strip in the pocket. Blinking distributes the med over the eye. May have systemic effects!

How long does it take for a drug to mostly leave the body after it is discontinued?

When drug administration is discontinued, most (94%) of the drug in the body will be eliminated over an interval equal to about four half-lives.

Give an example of when the use of each name (generic or trade) might be appropriate?

When large numbers of drug names are unfamiliar or not standardized, as is common with many trade names, it creates the potential for confusion. For this reason, many professionals advocate for the universal use of generic names. For instance, use of trade names can result in "double medication" - with potentially disastrous results. Because patients frequently see more than one healthcare provider, a patient may receive prescriptions for the same drug by two (or more) prescribers. If those prescriptions are written for different brand names, then the two bottles the patient receives will be labeled with different names. Consequently, although both bottles contain the same drug, the patient may not know it. If both medications are taken as prescribed, excessive dosing will result. However, if generic names had been used, both labels would bear the same name, thereby informing the patient that both bottles contain the same drug.

Combination drugs

When preparing these drugs you MUST know all parts of the combined drug Percocet (acetaminophen and oxycodone) Anacin (aspirin and caffeine) Advair (fluticasone and salmeterol)

Drug Incompatibility

When putting 2 drugs in the same syringe or same IV/tubing can form precipitate or a lethal new substance Careful: Two medications most often cannot be mixed together in a syringe for administration May cause precipitation May inactivate drug properties When in doubt, check it out: - Look up in chart - Consult with pharmacist - When in doubt don't administer together

Renal failure and pharmacokinetics

When the kidneys are healthy, they serve to limit the duration of action of many drugs. Conversely, if renal failure occurs, both the duration and intensity of drug responses may increase, leading to toxicity.

Types of drug orders

Written Verbal, telephone, fax Routine Prn (as needed, not "as desired"; collaboration between client, family/SO, care providers) Stat Standing orders: all persons with same dx/procedure Protocol

Prodrugs

a compound that is pharmacologically inactive as administered and then undergoes conversion to its active form via metabolism. Example: the metabolic conversion of fosphenytoin to phenytoin.

Iatrogenic disease

a disease that occurs as the result of medical care or treatment. The term iatrogenic disease is also used to denote a disease produced by drugs.

"Lethal Dose 50" LD/50

a dose at which 50% of subjects (usually animals) will die

Teratogenic effect

a drug-induced birth defect. Medicines and other chemicals capable of causing birth defects are called teratogens.

Allergy

a histamine-mediated response, from mild to lethal

Lotion

a liquid medicinal preparation for local application to, or bathing of, a part

Fluid extract

a liquid preparation, containing alcohol as a solvent or as a preservative, that contains in each cubic centimeter the medicinal activity of one gram of the crude drug in powdered form

Paste

a mixture of an ointment and a powder, having a semisolid consistency

Allergic reaction

a reaction resulting from hypersensitivity to an allergen. An immune response

Gel or jelly

a semisolid precipitated or coagulated colloid; a jelly-like colloid; jelly. It contains a large amount of water

Physical dependence

a state in which the body has adapted to drug exposure in such a way that an abstinence syndrome will result if drug use is discontinued. Physical dependence develops during long-term use of certain drugs, such as opioids, alcohol, barbiturates, and amphetamines. The precise nature of the abstinence syndrome is determined by the drug involved. Because a variety of drugs can cause physical dependence of one type or another, and because withdrawal reactions have the potential for harm, patients should be warned against abrupt discontinuation of any medication without first consulting a health professional.

Anaphylaxis

a sudden, severe allergic reaction between an allergenic antigen and immunoglobulin E (IgE) bound to mast cells, which stimulates the sudden release of immunological mediators locally or throughout the body. The first sysmptoms can occur within minutes, and a recurrence may follow hours later (late-stage response). Anaphylaxis can only occur in someone previously senitized to an ellergen because the initial exposure causes immunoglobulin E (IgE) to bind to mast cells. Anaphylaxis may be local or systemic. Local anaphylactic reactions include hay fever, hives, and allergic gastroenteritis. Systemic anaphylaxis produces peripheral vasodilation, bronchospasm, and laryngeal edema and can be life-threatening.

Elixir

a sweetened, aromatic, hydroalcoholic liquid used in the compounding of oral medicines. Elixirs constitute one of the most common types of medicinal preparation taken orally in liquid form

Problems with adequate blood flow for distribution

abscess solid tumors Shock

What are the 4 parts of Pharmacokinetics?

absorption, distribution, metabolism, excretion

Often extensions of the therapeutic effects: "too much of a good thing"

adverse effects

Cumulative

alcoholics & ESRD

"Effective Dose 50" ED/50

amount of drug that produces a therapeutic response in 50% of the people taking it

Steady state

amount taken in = amount excreted

Idiosyncratic response

an uncommon drug response resulting from a genetic predisposition. A classic example of an idiosyncratic effect occurs in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is an X-lined inherited condition that commonly occurs in people with African and Mediterranean ancestry. When people with G6PD deficiency take drugs such as sulfonamides or aspirin, they develop varying degrees of red blood cell hemolysis, which may become life threatening.

Ventrogluteal sites

are safest in adults and cause least pain

Inactive ingredients

are usually harmless substances that do not affect the body. However, because inactive ingredients can cause unusual and sometimes severe allergic reactions in a few people, one version, or brand, of a drug may be preferable to another.

Hepatotoxic drugs

as some drugs undergo metabolism by the liver, they are converted to toxic products that can injure liver cells. These drugs are called hepatotoxic drugs.

Enzyme Competition

between drugs for the enzyme systems: may need to decrease doses Demerol and Vistaril are given together (potentiation) because they compete for the same metabolic enzyme

Generic drugs can be chemically the same (same active ingredient) but may differ in ______________________

bioavailability This is most dangerous with drugs that have a narrow range of dosing safety Variance primarily occurs with oral drugs Thyroid meds, oral theophylline (asthma) Drug manufacturing is different for different brands Use of different binders may affect pH or solubility Explains why generic brands are not recommended for certain drugs

The placental barrier does not keep most drugs from the fetus. Fetal drug exposure, especially during the 1st trimester, can cause what?

birth defects and fetal abnormalities.

Lipid solubility

capable of dissolving in fats, oils, or fatty tissues. (p. 24) A general rule in chemistry states that "like dissolves like." Membranes are composed primarily of lipids; therefore, to directly penetrate membranes, a drug must be lipid soluble (lipophilic). Direct penetration of the membrane is the most common way by which drugs cross cell membranes because (1) most drugs are too large to pass through channels or pores, and (2) most drugs lack transport systems to help them cross all of the membranes that separate them from their sites of action, metabolism, and excretion.

Blood brain barrier

capillary epithelium has almost no space between, reducing the ability of many drugs to pass through only drugs that are very soluble, have small molecular size, and do not bind with plasma proteins well will diffuse across brain cell membranes restricts access to the cerebrospinal fluid for most drugs. However, natural substances and some drugs are recognized as "friendly molecules" by the blood brain barrier mechanisms, and can easily penetrate through the barrier

Sustained released

capsules that result in slow and steady drug levels, less frequent dosing, SLOWS

In order to do absorption, distribution, metabolism, and excretion, drugs have to cross ___________________

cell membranes

Buccal

cheek or lip

Constitutes a description of a drug using the nomenclature of chemistry

chemical name

The four pharmacokinetic processes, acting in concert, determine the ____________________________________

concentration of a drug at its sites of action

What may happen when a client is taking more than one QT interval drug?

concurrent use of two or more QT drugs should be avoided, as should the concurrent use of a QT drug with another drug that can raise its blood level (eg, by inhibiting its metabolism).

Food generally ______________ drug absorption and increases variability of absorption rate

decreases

Transdermal patch

delivery system allows for steady prolonged absorption; change 1-7 days

Contraindicated IM injection sites in infants

deltoid & dorsogluteal sites

Compliance

did they do what they were told? (obedience model)

Drugs with narrow/low TI are _________________ by RNs: heparin, IV narcotics, insulin

double-checked

Drug classes

drug components (opioid) their therapeutic effects (analgesic) the symptom/body part affected (antihypertensives) receptor site affected (beta 2 agonist) neurotransmitter affected (SSRI) legal status (schedule II, controlled)

Steady State (Plateau)

drug excreted = drug administered reached in 4.5 half lives quicker plateau (steady state) when a loading dose is ordered

Distribution

drug movement from the blood to the interstitial space of tissues and from there into cells

Metabolism & excretion impact ____________ of action

duration Duration is the overall time of drug action, beginning to end.

more roles for the RN in addition to administration:

education knowledge of the drug and client documentation systems monitoring effects and client adherence knowledge of alternatives 2010 Institute of Medicine (IOM): Nurses need to get smarter, more science in their education

Side effects are much more common in the ______________ than in young adults

elderly

The combination of metabolism plus excretion is called ________________

elimination

Passive diffusion

from more to less one-way best with non-ionized molecules molecules must be small, easily soluble in lipids, and lack an electrical charge when the extracellular fluid and cellular fluid are "equal" in terms of the ions or molecules, passive diffusion stops

A term referring to the chemical makeup of a drug rather than to the advertised brand name under which the drug is sold. A term referring to any drug marketed under its chemical name without advertising.

generic name

Idiosyncratic

genetic predisposition

Cannot give any medication without assessing for a _______________ of drug and food allergies.

history

Kinetics

how drugs move in the body Absorption, distribution, metabolism, and excretion The effect of the body on drug action

Rate of dissolution

how easily does the drug dissolve/break down "Alka-Selzer"

Drugs that interact are often still given, but we must

increase assessment of therapeutic and adverse effects The more meds, the more risk of interactions Accurate history of all drugs including OTC, vitamins, teas, herbal preparations Assess most carefully following the addition of a new medication to regime

Resistance

ineffective related to certain pathogens

Grapefruit juice: INCREASES drug effects

inhibits intestinal metabolism (inhibits P450): increases drug absorption and hence, drug effects (most drugs) effect can be delayed (juice in am; drug in pm: may still effect) highly individual: not all persons have this response COMMON CULPRITS: - certain antihypertensives (calcium channel blockers) - CAFFEINE (extreme effect) - Estrogen - Statins

How does pregnancy change absorption?

intestinal transit time may be decreased (increases drug absorption)

Pharmacodynamics

is defined as the study of the biochemical and physiologic effects of drugs and the molecular mechanisms by which those effects are produced. In short, it is the study of what drugs to do the body and how they do it.

Combination products

know what it contains and evaluate for each product

Wide therapeutic range

large difference between therapeutic and toxic levels tend to be safer drugs.

Body surface area

larger area, quicker the absorption most oral drugs are absorbed in small intestine, rather than the stomach

Only FREE - not protein-bound - drug molecules are able to ____________ the blood stream and create drug action

leave

Tolerance

less effective over time

Clients at risk for drug toxicity due to immature or unhealthy livers should get _________ doses

lower Premature infants or newborns Liver damage (check for elevated or relatively absent liver enzymes) - Liver failure - Alcoholism - Hepatitis

MAO inhibitors & tyrosine

major antidepressant tyrosine: red wine, cheese, processed meats severely increases MAO availability and may have a hypertensive episode and stroke

Teratogenesis

malformations, or deficits in performance of body systems physical, skeletal, organ development, metabolic disorders, learning disorders?

How does pregnancy change metabolism?

may be increased for some drugs, particularly anticonvulsants

Lipid solubility

more lipid solubility -> better movement across cell membrane into blood stream

Antagonist/Reversal/Antidote

naloxone/Narcan for opioids

Dependence/Addiction

need repeated amounts to prevent withdrawal symptoms

Toxicity

occurs when plasma drug levels climb too high. The plasma level at which toxic effects begin is termed the toxic concentration.

Side effect

often expected effects even when appropriate doses are given.

Solution

oily vs aqueous (clear or cloudy such as insulin; clear is faster than cloudy usually

"On empty stomach"

one hour before or 2 hours after meal

Time it takes for drug effects to be felt

onset

Absorption & distribution mostly impact __________ of action

onset Onset: the time it takes for drug to START to work

What are clinical signs of liver toxicity?

patients taking hepatotoxic drugs should undergo liver function tests (LFTs) at baseline and periodically thereafter. How do we assess liver function? By testing a blood sample for the presence of two liver enzymes: aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Under normal conditions blood levels of AST and ALT are low. However, when liver cells are injured, blood levels of these enzymes rise. LFTs are performed on a regular schedule (eg, every 3 months) in hopes of detecting injury early. Because drug-induced liver injury can develop very quickly between scheduled tests, it is also important to monitor the patient for signs and symptoms of liver injury, such as jaundice (yellow skin and eyes), dark urine, light-colored stools, nausea, vomiting, malaise, abdominal discomfort, and loss of appetite. Additionally, patients receiving hepatotoxic drugs should be informed about these signs of liver injury and advised to seek medical attention is they develop.

How drugs affect the body

pharmacodynamics

By Mouth

po Assess swallowing ability Assess GI status (vomiting, severe diarrhea) Sublingual & Buccal routes are not same as oral When drug can only given via oral route, route may not be included in the order (eg stool softener)  Give sitting upright with a full glass of water

Nurses must practice anticipatory thinking to prevent:

potential errors in administration adverse effects drug-drug interactions (birth control pills and antibiotics and anti-epileptics) KNOW: We cannot always prevent or anticipate, so we must assess our clients carefully and teach the clients to carefully self-assess.

Always assess a patient for allergies __________ to administering any medication. Then assess afterwards and ongoing, if a routine med. Allergic responses may not be _________________

prior, immediate

Identify when in gestation the following occurs: Gross malformations

produced by exposure to teratogens during the embryonic period (roughly the first trimester). This is the time when the basic shape of internal organs and other structures is being established. Because the fetus is especially vulnerable during the embryonic period, pregnant patients must take special care to avoid teratogen exposure during this time.

Metabolism for most drugs leads to a _______________ of active drug in the body

reduction Metabolism (= biotransformation) - enzymatic alteration of drug structure  Mainly occurs in the liver ***Usually metabolic processes chemically changes drug so it can be excreted

How does pregnancy change excretion?

renal blood flow is doubled, causing a great increase in filtration, causing more excretion and less drug effects

Participants in clinical trials ____________ often.

self-select

Filtration or osmotic pressure gradient difference

similar to active transport, but it is a pressure gradient (not a protein pump) that gives the extra help.

Contraindications

something (such as a symptom or condition) that is a medical reason for not doing or using something (such as a treatment, procedure, or activity)

Identify when in gestation the following occurs: Functional problems

teratogen exposure during the fetal period (ie, the second and third trimesters) usually disrupts function rather than gross anatomy. Of the developmental processes that occur in the fetal period, growth and development of the brain are especially important. Disruption of brain development can result in learning deficits and behavioral abnormalities.

Carcinogenic effect

the ability of certain medications and environmental chemicals to cause cancers. Fortunately, only a few therapeutic agents are carcinogenic. Ironically, several of the drugs used to treat cancer are among those with the greatest carcinogenic potential.

Absorption

the movement of a drug from its site of administration into the blood

Excretion

the movement of drugs and their metabolites out of the body

Who is the "last line of defense" related to drug errors, according to the text?

the nurse

Duration

the period of time something has been present.

Bioavailability

the rate and extent to which an active drug or metabolite enters the body, permitting access to the site of action. Determined either by measurement of the concentration of the drug in body fluids or by the magnitude of the pharmacologic response.

Onset

the time between the administration of a medication or other form of treatment and the first evidence of its effect.

Drug half-life

the time required for the amount of drug in the body to decrease by 50%.

Half-life

time it takes for 50% excretion THIS determines dosage & frequency

Cross-Tolerance

tolerant to alcohol may need increased narcotics for pain

Distinguished to consumers as being produced and marketed exclusively by a particular manufacturer. Multiple names may exist for a particular generic name. Is capitalized.

trade (brand) name

Facilitated diffusion

uncommon glucose primarily uses a carrier protein in the extracellular fluid and rides it into the cell

Sublingual Buccal- cheek or lip

under tongue Fast response, often 5-10 min, Sometimes faster than IV route! nitroglycerine, morphine

Adverse effects may mimic signs of aging (and myths of aging), so adverse drug effects go __________________

undetected gait and balance disturbances sensory problems (ototoxicity, blurred vision) sedation or behavioral changes

Adherence

was the plan followed? If not, what are the reasons (cooperative model)

Generally the best drug choice is:

what creates the most benefit with the least harm

If we want client to "take with food":

with food just then or give just following a meal

What are the pharmacodynamic changes in the elderly?

• Alterations in receptor properties may underlie altered sensitivity to some drugs. However, information on such phamacodynamic changes is limited. In support of the possibility of altered pharmacodynamics is the observation that beta-adrenergic blocking agents (drugs used primarily for cardiac disorders) are less effective in older adults than in younger adults, even when present in the same concentrations. Possible explanations for this observation include (1) a reduction in the number of beta-receptors and (2) a reduction in the affinity of beta receptors for beta-receptor blocking agents. Other drugs (warfarin, certain CNS depressants) produce effects that are more intense in older adults, suggesting a possible increase in receptor number, receptor affinity, or both. Unfortunately, our knowledge of pharmacodynamics changes in older adults is restricted to a few families of drugs.

How are the pharmacokinetic components changed in the elderly?: Metabolism

• Decreased hepatic blood flow • Decreased hepatic mass • Decreased activity of hepatic enzymes

How are the pharmacokinetic components changed in the elderly? : Excretion

• Decreased renal blood flow • Decreased glomerular filtration rate • Decreased tubular secretion • Decreased number of nephrons

How are the pharmacokinetic components changed in the elderly? : Distribution

• Increased body fat • Decreased lean body mass • Decreased total body water • Decreased serum albumin • Decreased cardiac output

How are the pharmacokinetic components changed in the elderly? : Absorption

• Increased gastric pH • Decreased absorptive surface area • Decreased splanchnic blood flow • Decreased GI motility • Delayed gastric emptying

What percentage of elderly fail to take their medications as prescribed?

•Between 26% and 59% of older adult patients fail to take their medicines as prescribed •Some patients never fill their prescriptions, some fail to refill their prescriptions, and some don't follow the prescribed dosing schedule. •Non-adherence can result in therapeutic failure (from under-dosing or erratic dosing) or toxicity (from overdosing). Of the two possibilities, under-dosing with resulting therapeutic failure is by far (90%) the more common problem. Problems arising from non-adherence account for up to 10% of all hospital admissions, and their management may cost over $100 billion a year •Multiple factors underlie non-adherence to the prescribed regimen. Among these are forgetfulness; failure to comprehend instructions (because of intellectual, visual, or auditory impairment); inability to pay for medications; and use of complex regimens (several drugs taken several times a day). All of these factors can contribute to unintentional non-adherence. However, in the majority of cases (about 75%), non-adherence among older adults is intentional. The principal reason given for intentional non-adherence is the patient's conviction that the drug was simply not needed in the dosage prescribed. Unpleasant side effects and expense also contribute to intentional non-adherence.

What can be done to improve adherence to a drug regimen in the elderly?

•Simplifying the regimen so that the number of drugs and doses per day is as small as possible •Explaining the treatment plan using clear, concise verbal and written instructions •Choosing an appropriate dosage form (eg, a liquid formulation if the patient has difficult swallowing) •Requesting that the pharmacist label drug containers using a large print size, and provide containers that are easy to open by patients with impaired dexterity (eg, those with arthritis) •Suggesting the use of a calendar, diary, or pill counter to record drug administration •Asking the patient if he or she has access to a pharmacy and can afford the medication •Enlisting the aid of a friend, relative, or visiting healthcare professional •Monitoring for therapeutic responses, adverse reactions, and plasma drug levels

Primary Causes of Medication Errors

Interruption/Distraction (most common) Labeling Supervision Competency/Knowledge Training

Principles of drug use in pregnancy *Know these*

1. Avoid 1st trimester (1-12 weeks) if possible 2. If women are of childbearing age, they may be pregnant 3. Counsel prior to pregnancy if on long-term drugs 4. Necessary treatment should not be stopped just due to pg (example: asthma regimens) 5. Pregnancy may change drug levels and, thus, dosages may be decreased or increased (example: need more antidepressant dosage in 2nd trimester) 6. Use short-acting drugs, and avoid combination drugs (example: Use saline drops nasally, rather than Nyquil for a cold) 7. Use lowest dose of safest drug 8. Use drugs if benefits outweigh risks 9. Use alternate routes if possible (inhaled, topical) to increase selectivity 10. Use drugs with an established history of use in pregnancy

Drug Interactions have the capability of:

1. Intensify therapeutic or adverse effects 2. Reduce therapeutic or adverse effects 3. Create a unique response Rarely does a person take just one medication

Blood Urea Nitrogen (BUN), adult norms

10-20 mg/dL

5:45 pm =

1745 hours

IV technology

1950s, not common until early 70s

How common are medication errors?

According to the Institute of Medicine (IOM), every year medication errors injure at least 1.5 million Americans, and kill an estimated 7000. The financial costs are staggering: among hospitalized patients alone, treatment of drug-related injuries costs about $3.5 billion a year.

What can be done to improve adherence to a drug regimen for children?

Achieving accurate and timely dosing requires informed participation of the child's caregiver and, to the extent possible, active involvement of the child as well. Effective education is critical. The following issues should be addressed: o Dosage size and timing o Route and technique of administration o Duration of treatment o Drug storage o The nature and time course of desired responses o The nature and time course of adverse responses Written instructions should be provided. For techniques of administration that are difficult, a demonstration should be made, after which the parents should repeat the procedure to ensure they understand. With young children, spills and spitting out are common causes of inaccurate dosing; parents should be taught to estimate the amount of drug lost and to re-administer that amount, being careful not to overcompensate. When more than one person is helping medicate a child, all participants should be warned against multiple dosing. Multiple dosing can be avoided by maintaining a drug administration chart. With some disorders - especially infections - symptoms may resolve before the prescribed course of treatment has been completed. Parents should be instructed to complete the full course nonetheless. Additional ways to promote adherence include (1) selecting the most convenient dosage form and dosing schedule, (2) suggesting mixing oral drugs with food or juice (when allowed) to improve palatability, (3) providing a calibrated medicine spoon or syringe for measuring liquid formulations, and (4) taking extra time with parents to help ensure conscientious and skilled participation.

Treatment goals for pharmacotherapy

Acute Maintenance Supplemental/Supportive Palliative Prophylactic Empiric

How long does it take for a drug level to reach plateau?

Administering repeated doses will cause a drug to build up in the body until a plateau (steady level) has been achieved When a drug is administered repeatedly in the same dose, plateau will be reached in approximately four half-lives.

How often do adverse drug reactions occur in the elderly, compared to younger adults?

Adverse drug reactions (ADRs) are 7 times more common in older adults than in younger adults, accounting for about 16% of hospital admissions among older individuals and 50% of all medication-related deaths

Trade name

Also known as proprietary or brand names, are the names under which a drug is marketed. These names are created by drug companies with the intention that they be easy for nurses, physicians, pharmacists, and consumers to recall and pronounce. Since any drug can be marketed in different formulations and multiple companies, the number of trade names that a drug can have is large. The FDA must approve trade names. The review process tries to ensure that no two trade names are too similar.

Side effects

An action or effect of a drug other than that desired. It is commonly an undesirable effect such as nausea, headache, insomnia, rash, confusion, dizziness, or an unwanted drug-drug interaction. Are nontherapeutic reactions to a drug that are transient and may not require any nursing intervention. (p. 62) A side effect is formally defined as a nearly unavoidable secondary drug effect produced at therapeutic doses. Side effects are generally predictable, and their intensity is dose dependent. Some side effects develop soon after drug use starts, whereas others may not appear until a drug has been taken for weeks or months.

Tincture

An alcoholic extract of vegetable or animal substances

Non-receptor effects (not all drugs work by affecting receptor sites)

Antacids (neutralizes acid only) Anticoagulants (neutralizes electrical charge on a plasma protein needed to initiate blood clotting) Anticancer drugs (disturbs mRNA formation in the cell, leading to ineffective cellular processes)

Drug

Any chemical that can affect living processes

Adverse effects

Any noxious, unintended, and undesired effect that occurs at normal drug doses. Adverse reactions can range in intensity from mildly annoying to life threatening. Nontherapeutic effects that may be harmful to the patient that requires lowering the dosage or discontinuing the drug.

Protein binding

Drugs can form reversible bonds with various proteins in the body. Of all the proteins with which drugs can bind, plasma albumin is the most important, being the most abundant protein in plasma. Like other proteins, albumin is a large molecule, having a molecular weight of 69,000 Daltons. Because of its size, albumin always remains in the blood stream. Albumin is too large to squeeze through pores in the capillary wall, and no transport system exists by which it might leave. Note than drug molecules are much smaller than albumin (The molecular mass of the average drug is about 300-500 Daltons compared with 69,000 Daltons for albumin.) Binding between albumin and drugs is reversible. Hence, drugs may be bound or unbound (free). The percentage of drug molecules that are bound is determined by the strength of the attraction between albumin and the drug. An important consequence of protein binding is restriction of drug distribution. Because albumin is too large to leave the bloodstream, drug molecules that are bound to albumin cannot leave either. As a result, bound molecules cannot reach their sites of action, or undergo metabolism or excretion until the drug-protein bond is broken. In addition to restricting drug distribution, protein binding can be a source of drug interactions. Each molecule of albumin has only a few sites to which drug molecules can bind. Because the number of binding sites is limited, drugs with the ability to bind albumin will compete with one another for those sites. As a result, one drug can displace another from albumin, causing the free concentration of the displaced drug to rise. By increasing levels of free drug, competition for binding can increase the intensity of drug responses. If plasma drug levels rise sufficiently, toxicity can result

Enzyme induction

Drugs that act on the liver to increase rates of drug metabolism are inducers. This process of stimulating enzyme synthesis is known as induction. As the rate of drug metabolism increases, plasma drug levels fall. Induction of drug-metabolizing enzymes can have two therapeutic consequences. First, if the inducer is also a substrate, by stimulating the liver to produce more drug-metabolizing enzymes, the drug can increase the rate of its own metabolism, thereby necessitating an increase in its dosage to maintain therapeutic effects. Second, induction of drug-metabolizing enzymes can accelerate the metabolism of other substrates used concurrently, necessitating an increase in their dosages.

If a drug is "highly lipid-soluble," is it easier or harder to cross cell membranes?

Easier Cell membranes composed of proteins, lipids and carbohydrates

Most important idea drug criteria

Effectiveness

Vastus lateralis

IM injection site recommended for infants

Routes and absorption generally, from fastest to slowest:

IV SL (almost as fast as IV), buccal Intrathecal, IM, SC, ID (discomfort/inconvenience) Nasogastric/orogastric tube PO - Safer than injection, potentially reversible Highly variable in absorption Possible inactivation by stomach acid & first pass Requires a conscious, cooperative client, who can swallow well. Irritation with good absorption: Increase in "stomach acid" Rectal Vaginal Eyes/Ears/Nose Topical/ transdermal

What is the difference between idiopathic and iatrogenic diseases?

Iatrogenic diseases are nearly identical to idiopathic (naturally occurring) diseases. For example, patients taking certain antipsychotic drugs may develop a syndrome whose symptoms closely resemble those of Parkinson's disease. Because this syndrome is (1) drug induced and (2) essentially identical to a naturally occurring pathology, we would call the syndrome an iatrogenic disease.

Drug-drug interactions can result in:

Increased risk of toxicity (Competition between 2 drugs for enzymes) Decreased drug effectiveness (Enzyme induction - speeds up metabolism Eg. barbituates, Nicotine)

Identify 3 ways to minimize adverse drug reactions?

•The responsibility for reducing ADRs lies with everyone associated with drug production and use. The pharmaceutical industry must strive to produce the safest medicines possible; the prescriber must select the least harmful medicine for a particular patient; the nurse must evaluate patients for ADRs and educate patients in ways to avoid or minimize harm; and patients and their families must watch for signs that an ADR may be developing and seek medical attention if one appears. •Anticipating ADRs can help minimize them. Nurses and patients should know the major ADRs that a drug can produce. This knowledge allows early identification of adverse effects, thereby permitting timely implementation of measures to minimize harm. •When patients are using drugs that are toxic to specific organs, function of the target organ should be monitored. The liver, kidneys, and bone marrow are important sites of drug toxicity. For drugs that are toxic to the liver, the patient should be monitored for signs and symptoms of liver damage (jaundice, dark urine, light-colored stools, nausea, vomiting, malaise, abdominal discomfort, loss of appetite), and periodic LFTs should be performed. For drugs that are toxic to the kidneys, the patient should undergo routine urinalysis and measurement of serum creatinine or creatinine clearance. For drugs that are toxic to bone marrow, periodic complete blood counts are required. •Adverse effects can be reduced by individualizing therapy. When choosing a drug for a particular patient, the prescriber must balance potential risks of that drug versus its probably benefits. Drugs that are likely to harm a specific patient should be avoided. For example, if a patient has a history of penicillin allergy, we can avoid a potentially severe reaction by withholding penicillin and contacting the prescriber to obtain an order for a suitable substitute. Similarly, when treating pregnant patients, we must withhold drugs that can injure the fetus. •Patients with chronic disorders are especially vulnerable to ADRs. In this group are patients with hypertension, seizures, heart disease, and psychoses. When drugs must be used long term, the patient should be informed about the adverse effects that may develop over time and should be monitored for their appearance.

What is the primary cause of ADRs in older adults?

•The vast majority of these reactions are dose related, not idiosyncratic. •Symptoms in older adults are often nonspecific (eg, dizziness, cognitive impairment), making identification of ADRs difficult •Perhaps surprisingly, the increase in ADRs seen in older adults is not the direct result of aging per se. Rather, multiple factors predispose older patients to ADRs. The most important are: oDrug accumulation secondary to reduced renal function oPolypharmacy (treatment with multiple drugs) oGreater severity of illness oThe presence of comorbities oGreater use of drugs that have a low therapeutic index (eg, digoxin, a drug for heart failure) oIncreased individual variation secondary to altered pharmacokinetics oInadequate supervision of long-term therapy oPoor patient adherence