A comparison of a hydrochlorothiazide plus triamterene combination (Dyazide) and atenolol in the treatment of patients with mild hypertension: A multicentre study in general practice

Abstract

SummaryOne hundred and eighteen patients with diastolic blood pressure between 95 and 110 mmHg were treated with the diuretic agents hydrochlorothiazide 25 mg plus triamterene 50 mg in combination, (Dyazide) initially one tablet, rising if required to two tablets per day, and 119 Patients were treated with atenolol (100 mg) in a multicentre, single blind randomised comparative study. Both treatments were associated with a significantly reduced supine and standing systolic and diastolic blood pressure within three weeks, with further reductions after six weeks.Atenolol produced an overall reduction in the mean of supine and standing diastolic and systolic blood pressure of 14 and 18 mmHg compared with 11 and 18 mmHg respectively for hydrochlorothiazide plus triamterene. Twenty four per cent of patients on hydrochlorothiazide plus triamterene had the dose of medication doubled after three weeks. After six weeks, 33 per cent of patients on hydrochlorothiazide plus triamterene and 26 per cent on atenolol had achieved a blood pressure of less than 140/95 mmHg (mean supine/standing).Nine patients in the hydrochlorothiazide plus triamterene group and eight in the atenolol group were withdrawn because of adverse events; additionally one patient on the diuretic combination died following a ruptured aortic aneurysm, which was considered to be unrelated to treatment. There was a higher overall frequency of adverse events in the atenolol group (0.64 events/patient) than in the hydrochlorothiazide plus triamterene group (0.49 events/patient). Mild hypokalaemia (minimum 3.3 mmol/l) occurred in three patients on hydrochlorothiazide plus triamterene, but more patients on atenolol were hyperkalaemic (maximum 6.0 mmol/1) at the end of the study. As expected, a higher proportion of patients on hydrochlorothiazide plus triamterene had elevated blood urea, serum creatinine and uric acid than on atenolol, although in no patient was treatment stopped because of the abnormal laboratory values.Both treatments were effective and generally well tolerated in the treatment of mild hypertension, the differences between them being of no clinical significance.