Combined use of nifedipine and diltiazem for the treatment of severe hypertension.

Calcium channel blockers are a heterogeneous group of drugs that have enhanced our ability to concurrently control blood pressure, treat coronary artery disease, and avoid many of the side effects of previously available antihypertensive agents. Patients with severe hypertension may require multiple agents for adequate control of blood pressure because of either poor control with one agent or side effects from high doses of a single agent. Laboratory investigations have shown a synergistic effect on receptor binding, as well as increased drug levels with the concurrent use of diltiazem and a dihydropyridine calcium channel blocker (nifedipine or nicardipine). It is as yet unknown whether these effects on receptor binding and increased drug levels translate into greater clinical efficacy in blood pressure control. We have reported what we believe to be the first case in which this interaction was used successfully to control previously poorly controlled hypertension, while minimizing side effects.