Nitrendipine and other calcium entry blockers (calcium antagonists) in hypertension

Nitrendipine is a calcium antagonistic 1,4-dihydropyridine derivative with a pronounced antihypertensive activity in animal experiment. Similar to other calcium entry blockers, nitrendipine decreases blood pressure by lowering the elevated peripheral vascular resistance. However, its long-term effect differs from that of vasodilators such as hydralazine and minoxidil. In contrast to vasodilators, nitrendipine reduces heart hypertrophy in various forms of experimental hypertension in rats. Nitrendipine is highly effective in normalizing blood pressure, reducing heart hypertrophy, and preventing mortality in salt-related hypertension (two-kidney renal hypertension, salt-induced hypertension in Dahl rats), which are rather refractory to the effect of vasodilators. Nitrendipine reduces renovascular resistance in spontaneously hypertensive rats but has no effect on that of normotensive rats. In conscious renal hypertensive dogs, nitrendipine decreases blood pressure more than does hydralazine. The reflex tachycardia is more pronounced after hydralazine than after nitrendipine; blood pressure decrease is greater and the duration of the effect is longer than that of nifedipine. Nitrendipine is thus predicted as an effective drug for antihypertensive monotherapy.