Safety and Efficacy of Therapeutically Equivalent Doses of Sustained‐Release Formulations of Isradipine and Felodipine

Abstract

This open-label, drug substitution study was conducted to determine if subjects receiving sustained-release isradipine (SR-I) can be safely switched to sustained-release felodipine (SR-F) and to assess whether SR-I provides better 24-hour blood pressure (BP) control than SR-F. Forty-one men receiving either SR-F 5 mg or SR-F 10 mg once daily for at least 6 months were switched to an equivalent dose of SR-I; BP was measured 2, 4, and 6 weeks after substitution. Significant reductions in systolic BP were seen in the SR-I 10 mg group after 4 weeks and they remained significantly lower through 6 weeks (p< or =0.05). Diastolic BP was reduced, but not significantly. After 6 weeks, SR-F therapy was reinstated, and BP returned toward baseline values. No serious adverse events were reported. SR-I can be safely substituted for SR-F and may provide better 24-hour control of BP than SR-F.

Comparison of Blood Pressure Control With Amlodipine and Controlled‐Release Isradipine: An Open‐Label, Drug Substitution Study

“…Despite similarities among these agents, however, recent evidence suggest that not all DHP CCBs are equivalent in terms of blood pressure (BP) control or incidence of treatment‐emergent side effects, such as pedal edema 8–10 . In particular, preliminary studies have found controlled‐release isradipine to produce lower rates of edema than amlodipine and controlled‐release felodipine, both intrinsically long‐lasting DHP CCBs 8,11 …”