Short-term efficacy of oral verapamil in rest angina. A double-blind placebo controlled trial in CCU patients.

To determine the efficacy and safety of oral verapamil in patients with rest angina admitted to the Coronary Care Unit (CCU), a double-blind placebo-controlled trial was undertaken. Of the 65 patients with rest angina screened for the study, 15 met the inclusion criteria (at least two episodes of chest pain associated with ST-T segment changes per 24 hours) during single-blind placebo phase (Day 1). Patients were then randomized to receive either placebo or verapamil (80 mg every 6 hours) on Day 2. Protocol was designed such that those who did not respond to the placebo (nonresponders) received verapamil, 80 mg every 6 hours, whereas verapamil nonresponders received increased doses (120 mg every 6 hours) on Day 3. Those who did respond (responders) continued to receive their medication. Similar action was taken on Day 4, depending on chest pain frequency and clinical evaluation. The study drug was unblinded on Day 4. At the end of the four-day period, 13 patients were receiving verapamil (nine patients, 80 mg every 6 hours, and four patients, 120 mg every 6 hours) and all but one were responders. One patient received placebo all through the period of the study and was also considered to be a responder. In the remaining one patient evidence of myocardial necrosis developed after he received a single dose of verapamil (80 mg on Day 2). Except for the prolongation of PR interval in two patients while taking verapamil, no side effects from verapamil therapy were observed. These data demonstrate the efficacy of oral verapamil in reducing episodes of myocardial ischemia in the majority of all patients with rest angina.