A comparison of atenolol and long-acting trimazosin in mild to moderate essential hypertension.

In a 12-week double-blind randomised study the efficacy of atenolol and a new longer-acting formulation of trimazosin were compared when given once daily in patients with mild to moderate hypertension. Two parallel groups, each consisting of 18 patients, were studied. At randomisation the two groups were well matched for age and sex distribution. They were also well matched for blood pressure, pulse rate and body weight; these latter measurements were recorded at regular intervals during the 12 weeks of study. Atenolol produced substantial reduction in both systolic and diastolic blood pressure, and in heart rate, during 12 weeks of treatment. This therapeutic effect was maintained until the next dose after 24 hours. Trimazosin, by comparison, failed to reduce either systolic or diastolic pressure, or to alter heart rate. Side effects were minor with both agents and compliance with treatment was good. Atenolol caused significant elevation of plasma concentration of triglyceride, with reduction in high density lipoprotein concentration when compared with trimazosin. In conclusion, atenolol was confirmed as an effective agent for the treatment of mild to moderate hypertension. By comparison trimazosin in the longer-acting formulation was ineffective in this study. However, trimazosin may still find a place in treatment if used at higher dose.

Effects of potassium on sodium balance, renin, noradrenaline and arterial pressure.

To determine the effects of potassium on blood pressure and factors affecting blood pressure, we conducted a randomized, placebo controlled trial of a potassium chloride-based substitute for table salt in 23 patients with mild to moderate essential hypertension. In addition, the effects of potassium chloride on sodium balance were studied in 10 normal subjects. Potassium loading with 100 mmol/day over five days in these normal subjects caused a cumulative negative sodium balance of 138 +/- 35 mmol, similar in degree to that achieved by severe dietary sodium restriction. However, two weeks of potassium treatment (100 mmol/day) in patients with essential hypertension did not lower blood pressure (BP) either in the supine or upright positions (potassium treatment: mean BP 108 +/- 3 lying and 113 +/- 3 mmHg standing; placebo treatment: mean BP 109 +/- 3 lying and 115 +/- 3 mmHg standing). Patients found it difficult to tolerate the potassium-based salt substitute in the dose given. We conclude that it is premature to recommend an increase in potassium chloride intake as treatment for raised blood pressure.

Mood changes during captopril therapy for hypertension. A double-blind pilot study.

A small double-blind pilot study was carried out to assess whether captopril treatment in hypertension has a euphoriant effect. Eight patients were maintained on constant therapy of atenolol and bendrofluazide for at least 4 weeks before and throughout the study. Captopril 25 mg three times daily or matching placebo was administered double-blind for 6 weeks, with crossover to placebo or captopril from Weeks 7 to 12. Psychiatric assessment was made at Weeks 3, 6, 9, and 12. During the captopril phase, blood pressure was reduced, plasma angiotensin II lowered, and plasma renin raised. Mood was slightly, but significantly, lower during captopril administration; thus, there was no evidence of an euphoriant effect of captopril. This pilot trial also indicates the feasibility of the approach, and such studies of hypertensives under therapy should be usefully extended and refined.