Monotherapy of stable angina with nicardipine hydrochloride: Double-blind, placebo-controlled, randomized study

The effect of nicardipine hydrochloride, a calcium-channel blocking agent, was studied in 46 patients with stable angina in a double-blind, placebo-controlled, randomized, repeated cross-over protocol, using a 30 or 40 mg dose of nicardipine or placebo three times a day. Mean resting heart rate and blood pressure did not change significantly with 30 mg nicardipine; heart rate increased from 81 ±10 to 88 ±13 beats min^-1, systolic blood pressure decreased from 129±18 to 119±16mmHg, and diastolic blood pressure from 81 ±12 to 74±11 mmHg (P < 0·01 for all three variables) with a 40 mg dose. Using a treadmill exercise protocol, mean exercise duration increased from 5·4±1·8 to 6·0±1·8 min (P<0·01) with 30 mg nicardipine, and from 5·8+1·7 to 616+1·9 min (P<0101) with 40 mg. Time to onset of angina increased from 4·6+1·9 to 5·2±1·7min (P<0·05) with 30 mg and from 5·1 ± 1·8 to 5·7+1·8 min (P = NS) with 40 mg. Mean anginal frequency and sublingual nitroglycerin consumption were low during the cross-over placebo period and did not change significantly during therapy with nicardipine. Non-cardiac side-effects were mild and required the withdrawal of only one patient from the study. However, during nicardipine therapy four patients had unstable angina and two developed a non-Q wave myocardial infarction. Of these patients, five were receiving a β-adrenergic blocker that was discontinued prior to the study. It is concluded that nicardipine had only a mild positive effect on exercise duration. As observed with other dihydropyridines, nicardipine has the potential to precipitate important ischaemic events in patients with stable angina, particularly when started after discontinuing a β-adrenergic blocking agent.