Tolerability of isradipine in the treatment of mild-to-moderate hypertension in general practice: a large-scale surveillance study.

The tolerability of isradipine was evaluated in an open trial of patients with mild-to-moderate essential hypertension as treated in general practice. The primary objective was to identify all adverse reactions, especially those that were newly occurring (greater than or equal to 6 reports), with a frequency greater than 1/1,000. Over 1,100 general practitioners and 5,526 patients participated in this trial. After a 2-week washout period, and a 3-week placebo run-in, patients with diastolic blood pressure (DBP) greater than or equal to 95 mm Hg were initially given isradipine at 1.25 mg twice daily. After 4 weeks, doses were doubled if DBP was greater than 90 mm Hg. If, after a further 4 weeks with doubled dosages, the DBP was still greater than 90 mm Hg, a second (nonspecified free-choice) antihypertensive agent was added to the treatment. Adverse events were recorded by open questioning. The incidence of adverse events was found to be similar to that with placebo; adverse events were generally mild or moderate in intensity and disappeared over time. No newly occurring adverse events were found. In conclusion, isradipine is safe and well tolerated at effective antihypertensive doses in patients with mild-to-moderate hypertension as treated in general practice.