CIGARETTE-SMOKING AND THE TREATMENT OF ANGINA WITH PROPRANOLOL, ATENOLOL, AND NIFEDIPINE

To determine whether cigarette smoking affects the results of drug treatment for angina, 10 cigarette smokers with angina were given placebo, nifedipine (60 mg/day), propranolol (240 mg/day) and atenolol (100 mg/day), each for 1 wk. The 4-wk double-blind study was repeated with the same randomly determined order of drug sequences, after all 10 subjects had stopped smoking. Before and after the subjects stopped smoking, all 3 drugs significantly reduced the frequency of angina, as measured with angina diaries, and improved the results of maximal exercise testing and 48-h ambulatory monitoring of ST segments (P < 0.01). During the nonsmoking phase of the study, there was an overall decline in the frequency of angina and an improvement in performance on exercise testing (P < 0.05) as compared with the smoking period, although the results of 48-h ambulatory monitoring remained unchanged. Improvement after patients stopped smoking was greater during treatment with nifedipine than during administration of the other 2 drugs or placebo. Blood levels of propranolol were increased when patients stopped smoking; levels of nifedipine and atenolol were unchanged. Smoking had direct and adverse effects on the heart and interfered with the efficacy of all 3 anti-anginal drugs, but with nifedipine the most.