[Efficacy and tolerability of isoptine LP in mild to moderate hypertension. A multicenter study with 50 patients].

A multicenter open trial involving 50 hypertension patients enabled evaluation of the efficacy and tolerability of Isoptine L.P. (sustained release verapamil) in mild to moderate essential hypertension. Following a 2-week placebo run-in period, patients were given Isoptine L.P. (240 mg/24 h) as a morning dose for 3 months, with a possible dose increase (360 mg/24 h) in case of diastolic blood pressure of 95 mmHg or more at the 30-day evaluation. Blood pressure was measured by mercury sphygmomanometer and, in 20 patients, by a Dinamap type Automatic device. After 3 months of treatment, blood pressure levels in supine and standing position, measured manually and automatically, showed a highly significant decrease, with a mean fall of 18.4 mmHg for systolic (13.7 percent) and 13.2 mmHg diastolic (-14.6 percent). 67 percent of patients were responders after 1 month of treatment and 79 percent at 3 months, including one-fifth at the dose of 360 mg/24 h. Seventeen patients, i.e. 34 percent, reported one or more adverse reactions. Among these, four patients had to stop treatment, twice because of headache and twice for constipation. Adverse events seen most frequently were constipation, headache, tiredness and vomiting. No cardiac adverse events were reported with the exception of one case of atrial premature contractions. The electrocardiogram revealed significant slowing of heart rate, as well as slight prolongation of PR and QT intervals and slight widening of the QRS complex. Tolerability on the basis of laboratory parameters was good.