AMLODIPINE VS NIFEDIPINE - A CROSSOVER STUDY OF EFFICACY AND TOLERABILITY IN PATIENTS WITH STABLE ANGINA-PECTORIS

A randomised crossover study was conducted to compare the efficacy and tolerability of amlodipine with that of slow release nifedipine in pa tients with stable exertional angina. After a 1-week drug washout phas e, 48 patients were treated for 4 weeks with amlodipine (5 to 10mg onc e daily) or slow release nifedipine (20 to 40mg twice daily) and then crossed over to the alternative regimen; dosages were titrated to resp onse within the dose range allowed. Both drugs were effective in contr olling cardiac ischaemia, as evidenced by a reduced incidence of angin al episodes (reported by patients and observed with Holter monitoring) and increased exercise tolerance. From the results of bicycle stress tests, both drugs appeared to reduce myocardial oxygen consumption dur ing dynamic exercise by limiting the increase in heart rate; these fin dings were also confirmed by heart rate and systolic blood pressure de terminations. Patients who received amlodipine during the second treat ment phase showed arterial pressures similar to those achieved with sl ow release nifedipine, but heart rates were lower. In contrast, patien ts treated with amlodipine during the first phase experienced a furthe r reduction in blood pressure and an increase in heart rate when subse quently treated with nifedipine; however, these results require additi onal confirmation. The incidence of adverse events was also lower duri ng treatment with amlodipine than with nifedipine. In conclusion, amlo dipine has an efficacy and tolerability profile that is at least as go od as that of slow release nifedipine in the treatment of patients wit h stable angina pectoris.