24 HOUR STABLE ANTI-ANGINAL EFFECT OF RETARD VERAPAMIL, DILTIAZEM & NIFEDIPINE

Abstract

maintain anti anginal effect throughout 24 hours. However the duration of effect and antianginal effect of
retard form of calcium antagonists has not been widely investigated.
Objective: The objective of this study was to asses the duration of effect, antianginal effect and tolerability
of retard forms of nifedipine, verapamil and diltiazem.
Methods: Patients with typical exertional chest pain and atleast 1mm ST-segment depression on ECG were
included in this study. Each patient under went control ETT. Then ETT was done after giving drugs at 4, 12
and 18 hours with each drug in all patients after an interval of 3-4 days. Mean ST-segment depression of all
leads was calculated and Δ% ST-segment depression was derived. The drug was considered effective if Δ%
ST-segment depression was more than 30%.
Result: With 20mg retard nifedipine, the Δ% ST-segment depression after 4 hours was 35.8% and after 12
hours was 45.2% with 120 mg retard verapamit, it was 36.4% after 4 hours 31.4% after 12 hours 25% after
18 hours with 240 mg of retard verapmit, it was 58.6% after 4 hours, 58.1% after 12 hours and 46.5% after
18 hours, with 90mg retard diltiazem it was 65.1% after 4 hours 49.9% after 12 hours and 16.4% after 18 hours.
Conclusion: All calcium antagonists in retard form have shown good anti ischemic and anti anginal effect
throughout 24 hours.