Pharmacology Basics Flashcards
7 cards from real PEBC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pharmacology Basics flashcards as text
Renal clearance of a drug is increased when the drug is:
Answer: Actively secreted by renal tubules
Active tubular secretion adds to glomerular filtration, substantially increasing total renal clearance beyond that predicted by filtration alone.
The therapeutic effect of a drug that acts as an enzyme inhibitor is most directly related to:
Answer: Accumulation of the enzyme's substrate or reduction of its product
Enzyme inhibitors reduce conversion of substrate to product, so substrate accumulates and/or product decreases, which is the basis of the therapeutic effect.
Which statement about drug half-life in first-order kinetics is TRUE?
Answer: Half-life is independent of the initial dose or concentration
In first-order kinetics, half-life is constant (t½ = 0.693/ke) and does not depend on the drug concentration or dose.
Upregulation of receptors is most commonly associated with:
Answer: Chronic antagonist exposure
Prolonged receptor blockade by antagonists leads to receptor upregulation, increasing the number or sensitivity of receptors, which can cause rebound effects if the antagonist is abruptly stopped.
Which phase I metabolic reaction is most commonly catalyzed by cytochrome P450 enzymes?
Answer: Oxidation
Oxidation is the predominant phase I reaction and is primarily carried out by cytochrome P450 (CYP) enzymes located mainly in the liver.
A patient with severe renal failure is prescribed a drug that is 90% renally excreted unchanged. What is the expected consequence?
Answer: Drug accumulation and increased risk of toxicity
In renal failure, a drug primarily excreted by the kidneys will accumulate because clearance is markedly reduced, increasing the risk of dose-dependent toxicity.
Which pharmacokinetic model assumes that the body acts as a single, well-mixed compartment for drug distribution?
Answer: One-compartment model
The one-compartment model assumes instantaneous and uniform drug distribution throughout the body, simplifying pharmacokinetic calculations.