Nifedipine (Procardia) is which type of drug, and what precaution is important?

• A. Calcium channel blocker antihypertensive; don’t give if hypotensive
• B. ACE inhibitor; avoid in hyperkalemia
• C. Beta-blocker; avoid in asthma
• D. Diuretic; avoid in kidney stones

Answer: (A)

Nifedipine is a calcium channel blocker of the dihydropyridine type used to treat hypertension. It works by blocking L-type calcium channels in vascular smooth muscle, causing arteriolar dilation and a drop in systemic vascular resistance, which lowers blood pressure. A key precaution is to avoid giving it if the patient is hypotensive, because further lowering the blood pressure can impair organ perfusion. Be sure to check blood pressure before administration and hold the medication if the systolic pressure is too low. Common side effects come from the vasodilatory effects, such as headache, flushing, edema, and sometimes palpitations. This drug is not an ACE inhibitor, beta-blocker, or diuretic, so those mechanisms and precautions don’t apply to nifedipine.