Multicentre isradipine dose-confirmation study in Thai patients with hypertension.

Isradipine is a new calcium antagonist of the dihydropyridine type, with marked vasodilator activity and minimum negative inotropic effects. It is a potent antihypertensive drug when given as monotherapy. This was a single-blind multicentre study consisting of 2 weeks' placebo pretreatment and 8 weeks' treatment with isradipine. After the placebo period, 90 patients aged 36 to 65 (mean 52) years with mild to moderate hypertension and diastolic blood pressures (DBPs) of greater than 95 to 114 mm Hg, were started on isradipine 1.25mg twice daily for 4 weeks. The dosage for the next 4 weeks was increased to 2.5mg twice daily if the DBP was greater than 90mm Hg. At the end of the study 72 of 90 patients (80%) had achieved a reduction in DBP greater than or equal to 10mm Hg and, of these, 48 (53%) had DBPs of less than or equal to 90mm Hg. This study confirms that isradipine 2.5mg twice daily is effective and well tolerated in the treatment of Thai patients with mild to moderate essential hypertension.