Calcium antagonists in the treatment of severe refractory hypertension.

Calcium antagonists such as nifedipine and verapamil, similarly to hydralazine (H) and minoxidil (M), act selectively on resistant arteriolar vessels; thus, they can be suitable for treating severe refractory hypertension. Nifedipine has been found safe and convenient even in elderly patients, both in emergency (sublingual capsules) and as long-term treatment. Unlike other vasodilators, it was easily tolerated, and was introduced as a replacement of H, M, and captopril (C) in combination therapy. Nitrendipine and felodipine have been found to be very effective on their own or in combination therapy, replacing H, M, C, and prazosin, whereas verapamil has been described by various authors as useful and rapidly effective when given intravenously to patients in hypertensive crises and in renovascular hypertension. The efficacy and relatively minor side effects of Ca antagonists would justify their inclusion in the treatment of severe hypertension.