The primary aim of this multicentre, randomised, double-blind, crossover study in 529 patients with stable angina pectoris was to compare the tolerability of epanolol, a novel antianginal agent, administered as a single oral daily dose of 200mg, with an oral retard formulation of twice-daily nifedipine 20mg and to determine patient preference (VISA 2). Confirmation of equal efficacy and safety monitoring were secondary aims of the study. Treatment consisted of 4 weeks on each therapy, and at the end of the study each patient was asked to state their treatment preference. 448 patients (85%) answered the preference question. Preliminary analysis of the data showed that 61% of patients preferred epanolol vs 31% who preferred nifedipine (p less than 0.001). Reason for a preference for epanolol were mainly fewer adverse experiences (11% vs. 23% with nifedipine), a general improvement in well-being (16% vs 10% with nifedipine) and a decrease in the number of angina attacks (11% vs 10% with nifedipine). A tolerability questionnaire comprising 43 questions and covering 7 different body systems showed that epanolol had a better profile than nifedipine for the following 7 side effects: poor sleep, abdominal pain, flushing, swollen ankles, palpitations, headache and a general feeling of being unwell. Four patients died during the study; none of the deaths were associated with the study treatment. Treatment with nifedipine resulted in 63 patient withdrawals compared with 31 patient withdrawals during epanolol treatment; there were 5 patient withdrawals from both treatments. The main reasons for withdrawal of patients from nifedipine treatment were adverse events (9% vs 4% with epanolol) and a lack of efficacy (3% vs 2% with epanolol).(ABSTRACT TRUNCATED AT 250 WORDS)