BHS Pharmacology and Therapeutics

Question 1

What term describes the time required for the plasma concentration of a drug to decrease by 50%?

Accepted Answer

Half-life

Answer

Half-life (t½) is the time it takes for the concentration of a drug in the bloodstream to be reduced by half, influencing dosing frequency.

Question 2

Which route of drug administration provides 100% bioavailability?

Accepted Answer

Intravenous (IV)

Answer

Intravenous administration delivers the drug directly into systemic circulation, bypassing first-pass metabolism and achieving 100% bioavailability.

Question 3

What is the 'therapeutic index' of a drug?

Accepted Answer

The ratio between the toxic dose and the effective dose

Answer

The therapeutic index (TI) is the ratio of the toxic dose to the effective dose, indicating how safe a drug is; a narrow TI requires careful monitoring.

Question 4

Which liver enzyme system is primarily responsible for the metabolism of most drugs in humans?

Accepted Answer

Cytochrome P450 (CYP450)

Answer

The cytochrome P450 enzyme family in the liver metabolizes the majority of pharmaceutical drugs, and interactions at these enzymes cause many drug-drug interactions.

Question 5

A patient taking a beta-blocker for hypertension develops bradycardia. This is an example of which type of drug effect?

Accepted Answer

Adverse drug reaction (side effect)

Answer

Bradycardia is a predictable side effect of beta-blockers due to their mechanism of slowing heart rate, classifying it as an adverse drug reaction.

BHS - Bachelor of Health Science Practice Test

BHS - Bachelor of Health Science Practice Test

BHS Pharmacology and Therapeutics