University of Illinois, Chicago

NURS 531

Chapter 9: Drug metabolism and elimination MULTIPLE CHOICE

1)Hepatic cytochrome P450 drug-metabolizing enzymes are primarily found in

1. cell nuclei
2. plasma membranes
3. the cytoplasm
4. the smooth endoplasmic reticulum
5. mitochondria

2.    Phase II drug metabolism

1. includes hydrolytic reactions
2. produces low molecular weight products
3. usually forms inactive metabolites
4. takes place mainly in the kidneys
5. requires NADPH as a cofactor

3.    Ketoconazole produces non-competitive inhibition of cytochrome P450 by

1. binding to the ferric form of heme iron
2. binding to the active site of the enzyme
3. causing enzyme autolysis
4. oxidizing NADPH
5. binding covalently to the P450 protein

4.    In first-order drug elimination

1. drug half-life is directly proportional to drug concentration
2. the rate of elimination is directly proportional to drug concentration
3. drug clearance is directly proportional to plasma drug concentration
4. the rate of elimination is constant
5. the rate of elimination is unpredictable

5.    If a drug is administered repeatedly at the same dose and dosage interval, the time required to reach the steady-state plasma drug concentration is proportional to the

1. dose
2. route of administration
3. dosage interval
4. bioavailability
5. elimination half-life