SUSTAINED-RELEASE VERAPAMIL AND AMBULATORY RECORDING OF BLOOD-PRESSURE IN MILD TO MODERATE ESSENTIAL-HYPERTENSION

An open study in 25 patients evaluated the efficacy and safety of Isoptine S.R., in some cases associated with Aldactazine in mild to moderate essential hypertension. After a placebo period of 2 weeks, the patients received sustained release verapamil (240 mg/24 hours) in a single morning dose for 6 months. An increase in the dosage (360 mg/24 hours in two subdoses) could be made during the first month of treatment if the diastolic blood pressure remained greater than or equal to 95 mmHg. If the diastolic blood pressure persisted at these levels at the second monthly assessment, a tablet of Aldactazine was associated. The blood pressure was evaluated by means of conventional clinical determinations and 24-hour ambulatory recordings carried out at the time of inclusion and then after 3 and 6 months of treatment. From the first month of treatment, the casual blood pressure determinations in the supine and standing position fell highly significantly (p < 0.0001), resulting in a mean reduction of 22.3 mmHg in the systolic blood pressure (-12.6 %) and of 17.4 mmHg in the diastolic blood pressure (-17 %). The ambulatory recordings of blood pressure also showed a significant reduction in the mean systolic blood pressure over 24 hours (p < 0.05 at the 3rd month of treatment), in the mean diastolic blood pressure over 24 hours (p < 0.01) and the mean pressure (p < 0.001). The reduction in systolic blood pressure was significantly greater in the << ambulatory hypertensive >> group (= mean diastolic blood pressure over 24 hours greater than or equal to 90 mmHg) (p < 0.02) than in the <<ambulatory normotensive>> group (= mean diastolic pressure over 24 hours < 90 mmHg) (not significant). In contrast, the fall in diastolic blood pressure was significant in both groups (p < 0.05 and p < 0.01 respectively). After one month of treatment, the percentage of responding patients was 88 per cent. Eight patients, or 32 per cent, reported an adverse effect of either constipation (7 cases) or headache (1 case). These adverse reactions were always moderate or transient and never led to discontinuation of treatment. One death occurred after the third month of treatment due to stroke. No clinical or electrocardiographic cardiac side effect occurred. The heart rate slowed slightly during treatment (p < 0.05). Laboratory safety parameters were good. This study did not reveal any predictive effect of the blood pressure profile on the efficacy of sustained-release verapamil. However, it did confirm the efficacy over 24 hours and the good safety of this calcium channel inhibitor.