Chapter 11: Drugs Used in Hypertension
A 32-year-old woman with hypertension wishes to become pregnant. Her physician informs her that she will have to switch to another antihypertensive drug. Which of the following drugs is absolutely contraindicated in pregnancy?
Methyldopa is often recommended in pregnant patients because it has a good safety record. Calcium channel blockers (choice D) and β blockers (choices A and E) are not contraindicated. In contrast, ACE inhibitors and ARBs (choice B) have been shown to be teratogenic. The answer is B.
A patient is admitted to the emergency department with severe tachycardia after a drug overdose. His family reports that he has been depressed about his hypertension. Which one of the following drugs increases the heart rate in a dose-dependent manner?
ACE inhibitors (choice A), ARBs (choice C), and diuretics (choice B) do not significantly increase heart rate. Although dihydropyridine calcium channel blockers do not usually reduce rate markedly (and may increase it), verapamil (choice E) and diltiazem do inhibit the sinoatrial node and predictably decrease rate. Other direct vasodilators (choice D) regularly increase heart rate, and minoxidil, a very efficacious vasodilator, causes severe tachycardia that must be controlled with β blockers. The answer is D.
Which one of the following is characteristic of nifedipine treatment in patients with essential hypertension?
(A) Competitively blocks angiotensin II at its receptor
(B) Decreases calcium efflux from skeletal muscle
(C) Decreases renin concentration in the blood
(D) Decreases calcium influx into smooth muscle
(E) Decreases calcium flux into the urine
Nifedipine is a prototype L-type calcium channel blocker and lowers blood pressure by reducing calcium influx into vascular smooth muscle. It has no effect on angiotensin-converting enzyme. Calcium efflux from skeletal muscle cells does not involve the L-type Ca channel. The plasma renin level may increase as a result of the compensatory response to reduced blood pressure. Calcium channel blockers have negligible effects on urine calcium. The answer is D.