Therapeutic Drug Monitoring (TDM) Certification Exam Questions With Correct Verified Answers.

Pharmacokinetics - correct answers -The study of how the human body handles drugs. -Deals with absorption, distribution, and elimination of drugs. -Mathematically characterizes distribution over time in order to better understand and interpret blood levels and effectively adjust dose amounts and dosing intervals. Minimum Effective Concentration (MEC) - correct answers Lowest concentration of drug in blood that will produce desired effect. Minimum Toxic Concentration (MTC) - correct answers Lowest concentration of drug in blood that will produce an adverse or toxic response. Therapeutic Index - correct answers Ratio of MTC to MEC varies from drug to drug and patient to patient. Peak Drug Level - correct answers -Highest concentration a drug reaches in the blood. It should not exceed the MTC. -Specimens for peak levels should be drawn and measured approximately 30 minutes after IV infusion. Trough Level - correct answers -Lowest concentration a drug reaches in blood. -Trough specimens should be drawn immediately before the next dose of drug is given and should not fall below MEC. Half-Life (T1/2) - correct answers -Time required for concentration of drug to be decreased by one half. -Half-life is different for each drug. -Example: If drug has 1/2 life of 4 hrs and plasma concentration was initially 100 ng/ml, 4 hours later, plasma concentration would be 50 ng/ml. Therapeutic Drug Monitoring - correct answers -Evaluation of levels of drugs prescribed for curative reasons. -Serum usually specimen of choice. -TDM measures blood level that correlates with tissue level. -Blood level is used to determine optimal dose. Therapeutic Range - correct answers -Drug level where most ideal effect is seen. -Amount of available drug that provides optimum amount of medication for treatment for clinical disorder. -Multiple dosing is required to each this level. Steady State - correct answers -Rate of administration of drug = rate of metabolism and excretion, allowing drug level to rain constant. -If first order kinetics are followed, drug approaches steady-state after 5-7 Half-Lives and peak & trough levels can be measured accurately. Specimen Collection - correct answers -Peak Levels: Draw within 30 minutes after IV infusion. -Trough Levels: Draw immedialty before the next dose is administered. Indications for TDM - correct answers -Drugs that have narrow therapeutic index. -Drugs subject to zero-order elimination kinetics. ----rate of metabolism fails to increase as concentration of drug increases. -Drugs used to treat symptoms that lack a definite clinical endpoint. (Anticonvulsants, antidepressants) -Drugs that demonstrate definite relationship between plasma drug level and clinical response. -Patients experiencing physiological and pathological changes: (Age, Pregnancy, Liver disease, Kidney disease, Congestive Heart failure, Gastrointestinal disease) Absorption - correct answers Ingestion into GI tract, intramuscular injection, intravenous injection Metabolism - correct answers Majority of drugs converted to there metabolites in Liver. The metabolites are excreted by the KIDNEYS. Distribution - correct answers -Albumin and alpha-1 glycoprotein are major proteins fro transport of drugs to cells. ---Only the unbound "FREE" portion is available for cellular uptake. ----Disease states that decrease serum protein may increase free drug concentration and elicit toxicity. Site of Drug Action - correct answers -TDM measures blood level that correlates with tissue level of drug. -Factors that can affect drug disposition: ---Patient's genetic make-up ---Patients medical condition ---Other medications ---Liver and Kidney function ---Age ---Pregnancy ----Stress ---Weight Excretion - correct answers -Majority of drugs and their metabolites are excreted via Kidneys -Glomeruli and tubules must be functioning properly Goal of TDM - correct answers -To ensure optimal drug level to benefit patient -To avoid toxicity. -Co-administration of Multiple Drugs (drug interference) -Assess patient compliance (Most common cause of suboptimal levels) *If drug does not have a toxic level, TDM may never be needed. Cardioactive Drugs - correct answers -Digoxin -Disopyramide -Lidocaine -Procainamide