RESUMEN
Beta-blockers and calcium antagonists are both effective monotherapy for stable angina. When symptoms persist, these two agents are commonly co-prescribed in the hope that this combination has added benefit compared with monotherapy alone. We investigated the additional efficacy of the calcium antagonists amlodipine and nifedipine when added to bisoprolol in patients with stable angina. Patients were randomised in a multicentre, single-blind study, with crossover of three treatments consisting of bisoprolol 10 mg once daily, bisoprolol plus nifedipine 20 mg twice daily, and bisoprolol plus amlodipine 5 mg once daily. Exercise tests were performed at the end of each four-week study period and the exercise time to onset of angina was assessed. A total of 198 patients from 17 centres were recruited of whom 147 were evaluable for efficacy. There were no statistically significant differences in exercise duration to onset of angina between any of the groups. The combination of bisoprolol plus nifedipine was least well tolerated. In summary, this study suggests there is little benefit in adding a calcium antagonist to bisoprolol in treating patients with stable angina.