Once daily timolol in the prophylaxis of angina pectoris

The clinical efficacy of timolol given once and twice daily was compared in the management of angina pectoris. Following a 2-week entry period, 16 normotensive male subjects with stable angina and proven myocardial ischaemia received timolol 10 mg twice daily, or 20 mg every morning for 1 month followed by 1 month on crossover therapy. All were exercised on separate days in random order 1 hr after administration of 10 mg, 1 hr after administration of 20 mg, 13 hr after administration of 10 mg and 25 hr after administration of 20 mg. In spite of significant differences in the maximum heart rates, rate pressure products and maximum lateral ST segment depression between the once and twice daily regimes, the maximal walking times were not significantly different (P greater than 0.10) and attack rates for angina and trinitrin consumption were similar (P greater than 0.45; P greater than 0.05). This evidence suggests that timolol is as effective in dosage of 20 mg taken once daily as half the dose taken twice daily in the symptom management of angina pectoris.