Effectiveness of nifedipine GITS in combination with atenolol in chronic stable angina

Nifedipine gastrointestinal therapeutic system (GITS) is a once-daily formulation of nifedipine that provides stable plasma concentrations over the entire 24 h dosing interval. Two-hundred and one patients with Canadian Cardiovascular Society class II to III angina who were on 50 mg of atenolol yet still experiencing angina symptoms were randomized to receive either placebo or nifedipine GITS 30, 60 or 90 mg/day. After four weeks of treatment, the changes in time from baseline to onset of 1 mm ST segment depression in the 183 eligible patients were 26.7+/-10.2 s, 40.9+/-11.3 s, 63.2+/-12.9 s and 70.3+/-12.6 for the placebo, and 30, 60 and 90 mg/day groups, respectively. These differences were significant (P<0.05) for the 60 and 90 mg/day groups compared with placebo and for the 60 mg/day group compared with the 30 mg/day group. The times to onset of pain and termination of exercise showed similar prolongation but did not achieve statistical significance. During the one-year open label phase of the study, patients exhibited statistically significant improvements in the time to onset of ST segment depression, time to anginal pain and time to termination of exercise at a mean dose of 52.3 mg/day of nifedipine GITS. Adverse events were primarily vasodilatory in nature. This study supports the use of nifedipine GITS in patients with chronic stable angina inadequately controlled on beta-blocker alone.