Does propranolol improve the duration and frequency of angina attacks in patients with coronary artery spasm?
Propranolol as a single therapy prolongs angina attacks in patients with coronary artery spasm and should not be used as sole treatment.
Using a double-blind protocol, we investigated the use of propranolol in patients with coronary artery spasm as assessed by subjective and objective variables. Both low-dose (40 mg every 6 hours) and high-dose (160 mg every 6 hours) propranolol were administered. At both doses, the duration of angina attacks was significantly prolonged but the frequency was not. We conclude that propranolol at doses up to 160 mg every 6 hours as single therapy is frequently detrimental in angina pectoris due to coronary artery spasm and should not be used as the sole treatment of this disorder.
Robertson et al. (Mon,) studied this question.