Individual factors influencing the response to a beta-adrenergic blocking agent given alone and in combination with a diuretic on arterial hypertension.

103 patients with arterial hypertension were treated with timolol + placebo for 7 weeks in a multicentre trial, and with timolol + hydrochlorothiazide and amiloride for a further 7-week period. The decrease in blood pressure (BP) produced by timolol alone was influenced neither by the dose of timolol, initial heart rate, magnitude of pretreatment BP nor by age. 64% of the patients less than 40 years of ages, and 48% of the older patients, were well regulated on beta-blocker monotherapy. When the diuretic was given in addition, the BP response in the older age group improved, whereas younger patients showed no change. A significant correlation was found between age or magnitude of untreated BP and the decrease in BP caused by the diuretic. The cardiothoracic ratio increased significantly on timolol alone, whereas no change was found on the combined therapy. Weight changes in the two different treatment periods showed a significant correlation, but they were not related to the observed reduction in BP. The results suggest that in younger patients, beta-blocker therapy is just as effective as a combined treatment with a diuretic, whereas in older patients considerably better regulation is achieved by combined therapy.