All the following induce hepatic enzymes except
- A. Rifampicin
- B. Phenytoin
- C. Barbiturates
- D. Tolbutamide
Correct Answer: D
Rationale: Tolbutamide does not significantly induce enzymes; others do.
You may also like to solve these questions
Chlorpropamide metabolism is enhanced by
- A. Ethyl alcohol
- B. Diazepam
- C. Lorazepam
- D. Chloridazepoxide
Correct Answer: A
Rationale: Ethyl alcohol induces hepatic enzymes, enhancing the metabolism of chlorpropamide, a sulfonylurea antidiabetic drug.
Thirty-two units of Humulin insulin is ordered for the patient. The insulin is supplied in a multidose vial that is labeled 100 units/mL. How much insulin would be needed to treat this patient?
- A. 0.032 cc
- B. 0.32 cc
- C. 3.2 cc
- D. 32 cc
Correct Answer: B
Rationale: A cc is equivalent to an mL. There are 100 units in each cc. Divide that amount by 32 units for the answer (0.32 cc).
A 66-year-old man is admitted to the hospital with confusion, nausea, and blurred vision. He is currently on digoxin for the treatment of heart failure. On physical exam, his heart rate is 120 bpm. Further evaluation reveals a digoxin level of 5.3 ng/mL (normal range: 0.5-2 ng/mL). The doctor believes his symptoms are due to digoxin toxicity. Which parameter is used to indicate the ability of digoxin to produce the desired effect relative to a toxic effect?
- A. Bioavailability
- B. Efficacy
- C. Intrinsic activity
- D. Therapeutic index
Correct Answer: D
Rationale: Therapeutic index (TI) measures the relative safety of a drug by comparing the dose required for a therapeutic effect to the dose that produces toxicity. In this case, digoxin toxicity is indicated by the elevated level, and TI is the relevant parameter.
To prevent life-threatening events from rapid withdrawal of a beta blocker:
- A. The dosage interval should be increased by 1 hour each day.
- B. An alpha blocker should be added to the treatment regimen before withdrawal.
- C. The dosage should be tapered over a period of weeks.
- D. The dosage should be decreased by one-half every 4 days.
Correct Answer: C
Rationale: Tapering over weeks prevents rebound hypertension or ischemia.
Sally has been prescribed aspirin 320 mg per day for her atrial fibrillation. She also takes aspirin four or more times a day for arthritis pain. What are the symptoms of aspirin toxicity for which she would need to be evaluated?
- A. Tinnitus
- B. Diarrhea
- C. Hearing loss
- D. Photosensitivity
Correct Answer: A
Rationale: Tinnitus is an early sign of aspirin toxicity (salicylism); diarrhea or photosensitivity are less specific, and hearing loss is later.