Define The Following Pharmacokinetics Terms Flashcards

State the three most important characteristics of any drug. Effectiveness, safety, and selectivity Is it possible to have a selective drug? No, all drugs can cause side effects Define pharmacokinetics: how much of the drug gets to the site of action via Absorption, distribution, metabolism, and excretion. Define pharmacodynamics. Determines nature and intensity of the response after binding to receptors Who is the most likely member of the health care team to observe and evaluate drug responses and to intervene if required? the nurse What are the three basic goals of pre administration assessment of medications Collecting baseline data (therapeutic and adverse responses), identify high-risk patients, assessing capacity for self-care. State the factors that can predispose an individual to adverse reactions from drugs Pathophysiology (liver and kidney dysfunction), genetics, allergies, pregnancy, age (very young/old). What are measures to reduce adverse effects of medication administration? Identify high-risk patients, ensure proper administration, educate patients that might precipitate an adverse reaction. Which Amendment strengthened drug regulation after the thalidomide tragedy in Europe? The Harris-Kefauver Amendments in response to a sedative that caused the birth defect phocomelia). What type of research is required to assess drug therapies? Randomized controlled trials What is a “blinded” study? People involved do not know to which group subjects have been randomized. Single: subjects blinded Double: researchers and subjects are blinded What is the purpose of having a trade name for a drug? Easy recall and pronunciation What is the problem with trade names? Clouds communication of the drug and promotes medication errors. What are the limitations of the testing procedures used to bring drugs to market? Testing is limited on women of childbearing age and children and the failure to detect all adverse effects. How much does it cost to develop a new drug in the US? $800 million State the four basic pharmacokinetic processes. Absorption, distribution, metabolism, excretion Highly lipid-soluble drugs are absorbed more (rapidly or slowly) than drugs whose lipid solubility is low? rapidly Define the term parenteral. Outside of the GI tract (sub-Q, IV, IM) At what rate should (intravenous) IV drugs be administered? Over 1 minute or more How long does it take an IV drug injected in the anti-cubital space to reach the brain? 15 secs What are depot preparations? Releases drugs slowly and steadily (EC, SR, ER) What types of compounds pass freely from the maternal bloodstream into the blood of the fetus? Lipid-soluble, non-ionized What kinds of compounds do not pass freely across the placenta? Ionized, protein bound, highly polar compounds What can occur when two highly protein bound drugs are given together? Faster metabolism of one or both of the drugs Give an example of a drug that is highly bound to protein. Warfarin (Coumadin) Drugs that are highly bound to protein may exhibit_____ levels in the blood when the patient is found with low albumin levels. Decreased Define biotransformation. metabolism Where does most drug biotransformation (metabolism) occur? liver If two drugs are given that both utilize p450 hepatic microsomal system, the drug level in the blood of the drug that is not metabolized ________. decreases At what age does hepatic maturation occur? 1 years old Drug metabolizing capacity in infants is (decreased or increased)? decreased How is the first-pass effect circumvented? Parental administration Define therapeutic range Between the minimal effective concentration and toxicity What aspect of pharmacokinetics primarily affects patients with kidney disease? excretion A drug with a narrow therapeutic range is (more or less) dangerous more Define drug half-life. The time required for amount of drug in the body to decrease by ½ How many half lives does it take for a drug to reach plateau? 4 half-lives Drugs that have a long half-life need to be administered (more or less) frequently than drugs that have a short half-life. less Agonists are molecules that (prevent or activate) receptor response? Activate Antagonists (activate or prevent) receptor activation? prevent Drugs that mimic the body’s own regulatory molecules are called agonist Define down-regulation and give an example of a medication that may lead to this effect. When a receptor has become less responsive to agonist Narcotics have that affect. Define ED-50 average effective dose What is the therapeutic index? Measure of a drug’s safety, a ratio of lethal dose/effective dose averages A drug with a high therapeutic index is considered (safe, or unsafe)? safe Laxatives (reduce or increase) absorption? reduce Drugs that depress peristalsis (reduce or increase) absorption? morphine and atropine When an inducing drug (phenobarbital) is taken with another medication, the metabolism of the other medication is increased Accelerated metabolism would lead to (increased or decreased) levels of the other drug? decreased (More or less) of the other medication would be needed? more to maintain blood levels Grapefruit juice can (inhibit or induce) the metabolism of certain drugs, thereby (raising or lowering)their blood levels? inhibit, raising What are the potential consequences when calcium channel blockers are taken with grapefruit juice? More intense effects on the blood pressure causing hypotension, tachycardia, headache, and flushing. How would you administer a drug “on an empty stomach”? 1 hr before or 2 hrs after a meal Patients over what age account for greater than 50% of adverse drug reactions (ADRs)? 60 When do side effects usually occur? Soon after onset of drug use Can an allergic reaction occur without prior sensitization? no Define an idiosyncratic effect from a drug and give an example. Uncommon response resulting from a genetic predisposition Define anaphylaxis A life threatening response characterized by brochospasm, laryngeal edema, and drop in blood pressure Why is abrupt discontinuation of a medication discouraged? physical dependence, and the withdrawal symptoms can be harmful if not fatal. What is the potential consequence of a medication that prolongs the QT interval? causing serious dysrhythmias Why are women at more risk for QT prolongation? Because their normal QT interval is longer than those in men. What is the most common cause of acute liver failure and hepatotoxicity? medications Define teratogenic. Drug-induced birth defect Define iatrogenic Disease produced by drugs What are the three most common causes of fatal medication errors? Human factors, miscommunication mistakes, and name confusion Why are the elderly more sensitive to drugs? Organ degeneration, hypersensitivity, severity of illness, polypharmacy, multiple pathologies. A patient with kidney or liver disease would require (higher or lower) dosages of a medicine? lower Define bioavailability Ability of a drug to reach circulation from site of administration Define the placebo effect. Component of drug response caused by psychological facts Define tachyphylaxis Form of tolerance caused by repeated doses of a short time frame (Nitro patch) Define tolerance Decreased responsiveness to a drug, resulting from repeated drug administration. A patient with glucose-6-phosphate dehydrogenase (G6PD) deficiency that takes aspirin or a sulfanilamide is at risk for what disorder? Hemolysis or destruction of red blood cells During pregnancy, increased renal blood flow leads to accelerated excretion of drugs. This process may require______in drug dosages? increase What class of blood pressure medication should not be taken during pregnancy? ACE-inhibitors Which FDA pregnancy risk category shows risk of fetal harm in women or animals whereby the risks clearly outweigh benefits? Category X Which antibiotics should not be taken during pregnancy? Tetracycline When is the best time to take a medication if breast feeding? After breastfeeding to reduce concentrations in the next feeding A neonate is defined as (less than or greater than) 4 weeks of age? less than Protein or albumin is (higher or lower) in and infant which might lead to_____ levels of a drug bound to protein? lower, decreased Hepatic metabolism and renal excretion in infants is (high or low)? Low in the beginning; newborn and through mid infancy, but reaches maturation by one year. (94) Why are neonates especially sensitive to drugs that affect the CNS The blood-brain-barrier is not fully developed The rate of drug absorption in the elderly is (slow or accelerated)? Slow because of delayed gastric emptying or reduced blood flow. (96) Drugs last longer in the elderly due to (decreased or increased) liver function Decreased, which causes longer ½ lives and decreased metabolism. What is creatinine clearance and why is it important in the elderly? It’s the proper index to assess renal function. This is important to assess because some drugs are excreted through the kidneys. What is the Beers criteria? Not needed, has a narrow therapeutic range, slowly excreted, and exclusively excreted through kidneys