1. A patient has been prescribed a medication that undergoes extensive hepatic metabolism. Which of the following enzymes primarily facilitates this metabolism? A) CYP2D6 B) CYP3A4 C) CYP2C9 D) CYP1A2 Answer: B) CYP3A4 Rationale: CYP3A4 is the major enzyme responsible for metabolizing a significant number of drugs through hepatic metabolism. This enzyme plays a crucial role in drug interactions and variability in drug response. 2. Which of the following pharmacokinetic parameters is used to determine the time it takes for the drug concentration to decrease by half in the body? A) Bioavailability B) Half-life C) Clearance D) Volume of distribution Answer: B) Half-life