A multicenter, double-blind, randomized, placebo-controlled study of isradipine and methyldopa as monotherapy or in combination with captopril in the treatment of hypertension. The LOMIR-MCT-IH Research Group

Abstract

This multicenter, double-blind, randomized trial of 1 year's duration compared the safety and efficacy of isradipine, methyldopa, and placebo in 368 men, aged 40 to 65 years, with mild-to-moderate essential hypertension. Initial treatment with isradipine (1.25 mg twice daily), methyldopa (250 mg twice daily), or placebo was started after a wash-out and single-blind placebo period. If normotension [diastolic blood pressure (DBP) < 95 mm Hg] was not achieved, doses were doubled. If the maximum dose as monotherapy did not result in normotension, captopril (25 mg or, if necessary, 50 mg, once daily) was added to the treatments of the three patient groups. Despite the marked placebo effect during the first 2 weeks of treatment, monotherapy with isradipine resulted in a higher rate of normalization (more than 64%) compared with 50% in the methyldopa group and 36% in the placebo group. Adding captopril to the treatments of non-responders increased the rate of normalization to 90% in the isradipine group, 84% in the methyldopa group, and 75% in the placebo group. Twenty-one patients dropped-out and 70 patients discontinued the study, the majority because of a lack of efficacy and adverse reactions. The most common adverse reactions reported were cardiovascular and gastrointestinal complaints, headaches, and sleep and sexual disorders, mostly by patients taking methyldopa. Isradipine was well tolerated and the side-effects were minimal. These results indicate that isradipine is superior to methyldopa and, whether as monotherapy or in combination with captopril, highly effective and well tolerated in the treatment of mild-to-moderate hypertension.