Nifedipine therapy in angina pectoris: evaluation of safety and side effects.

Nifedipine, a calcium-channel blocker, differs in structure and mode of action not only from the nitrates and beta blockers but also from the other well-known calcium-channel blockers. These differences have important implications for the treatment of angina pectoris. Our clinical experience over a period of 6 years with all types of angina patients--mostly those with chronic stable angina but also those with Prinzmetal's and unstable angina-corroborates the efficacy reports published in the world literature. Although the safety profile of nifedipine has been generally regarded as favorable, a few reports of clinically significant adverse effects in specific patient groups have appeared in the literature. In order to provide a more comprehensive assessment of safety, the records of over 3000 patients treated with nifedipine in open and controlled multiple-dose studies were tabulated and analyzed. Of special concern were patients with clinically significant adverse experiences, patients with a concomitant diagnosis of congestive heart failure (CHF), patients who were being treated concurrently with beta blockers, and patients who had been taking nifedipine for more than 6 months. Results of this analysis confirm that nifedipine can be safely administered to a broad spectrum of angina patients, including those with a concomitant diagnosis of CHF and those receiving concurrent therapy with beta-blocking agents.