Pharmacology Basics Flashcards

Tachyphylaxis refers to:

Answer: Rapid decrease in drug response following repeated administration

Tachyphylaxis is a rapid, short-term decrease in response to a drug after repeated doses, often due to receptor desensitization or depletion of mediators.

A drug with high plasma protein binding would be expected to have:

Answer: Reduced volume of distribution

Highly protein-bound drugs have less free drug in plasma to distribute into tissues, resulting in a lower apparent volume of distribution.

Which of the following best describes a prodrug?

Answer: An inactive compound converted to an active metabolite in the body

A prodrug is pharmacologically inactive and must be metabolized (typically by the liver) to an active form to exert its therapeutic effect.

The Henderson-Hasselbalch equation is used in pharmacology primarily to:

Answer: Predict the degree of drug ionization at a given pH

The Henderson-Hasselbalch equation relates pH, pKa, and ionization, allowing prediction of the proportion of ionized vs. non-ionized drug at a given pH.

Enteric coating on a tablet is designed primarily to:

Answer: Prevent dissolution until the tablet reaches the small intestine

Enteric coating resists gastric acid and dissolves only at the higher pH of the intestine, protecting acid-labile drugs or the gastric mucosa from irritating compounds.

Which type of drug interaction occurs when two drugs compete for the same plasma protein binding sites?

Answer: Pharmacokinetic displacement interaction

Displacement interactions occur when one drug displaces another from protein binding sites, transiently increasing the free (active) concentration of the displaced drug.

A drug that activates a receptor and produces the OPPOSITE effect of the endogenous ligand is called:

Answer: Inverse agonist

An inverse agonist binds to the same receptor as the agonist but stabilizes an inactive conformation, reducing constitutive activity and producing effects opposite to the agonist.