ABSTRACT
A randomized double-blind, comparative study, with a new slow release preparation of nifedipine (nifedipine-retard), was undertaken in patients with mild, moderate and severe essential hypertensión WHO (stage I-II). After a two-week placebo period, patients were divided into three groups: 1) group I received nifedipine-retard 20 mg orally twice daily; 2) group II received acebutolol 200 mg orally twice daily; and 3) group III received nifedipine-retard 20 mg once daily plus acebutolol 200 mg orally once daily. All three dosage regimens were administered for six weeks. Nifedipine-retard (group I) reduced supine blood pressure from 162 ñ 4.2/105 ñ 1.4 mmHg (21.6 ñ 0.5/14.0 ñ 0.2 Pa) to 139 ñ 4.2/92 ñ 2.6 mmHg (18.5 ñ 0.5/12.3 ñ 0.3 kPa) and slighrly increased the heart rate. Acebutolol (group I) reduced supine blood pressure from 163 ñ 5.3/107 ñ 2.8 mmHg (21.7-0.7/14.2 ñ 0.4 kPa) to 144 ñ 5.0/93 ñ 3.7 mmHg (192 ñ 0.7/12.4 ñ 0.5 kPa) and decreased the heart rate. Nifedipine retard plus acebutolol (group III) reduced supine blood presure from 144 ñ 3.0/101 ñ 1.3 mmHg (19.2 ñ 0.4/13.4 ñ 012 kPa) to 123 ñ 3.4/84 ñ 2.8 mmHg (16.4 ñ 0.5/11.2 ñ 0.4 kPa) and did not significantly alter the heart the heart rate. There was a significant correlation (r = 0.65, p < 0.03) betwee baseline blood pressure and diastolic blood pressure after six weeks of therapy nifedipine-retard. There was a no significant trend between the age of patients and decrease of diastolic blood pressure, positive for nifedipine-retard, and negative for acebutolol. There was a low incidence of side effects with all dosage regimens..