Comparison of hydrochlorothiazide and slow release furosemide as adjuvant therapy to beta-blockers in the treatment of moderate hypertension.

Fifty hypertensive patients on beta-blocker therapy with supine blood pressure greater than or equal to 95 mmHg were included in a parallel group, double-blind study for 12 weeks to compare blood pressures, metabolic and adverse effects of additional treatment with diuretics. Hydrochlorothiazide (HCT) 25 mg daily was added to one group and furosemide 30 mg daily in a slow-release preparation, Lasix Retard (LR), to the other. Blood pressure decreased significantly and similarly in both groups from about 155/101 to about 144/95 mmHg (p less than 0.01). Diastolic blood pressure was lowered to less than or equal to 90 mmHg in 29% of the HCT patients and in 59% of the LR patients. Serum potassium decreased significantly from 4.05 mmol/l to 3.62 mmol/l on HCT, while the decrease on LR from 4.13 mmol/l to 4.05 mmol/l was not significant. Serum urate increased significantly, although within the normal range, on HCT. No change in fasting blood glucose or HbA1C was observed in any group. The patients were asked to report 40 different possible side-effects on a visual analogue scale at every visit. The side-effects already observed on beta-blockers did not change consistently on additional therapy with either HCT or LR. Thus, additional treatment with HCT or LR to patients already treated with beta-blockers results in an equal further blood pressure reduction, but in contrast to treatment with HCT, addition of LR does not affect serum potassium concentrations.

RCT Entities:   Population Interventions Outcomes