Age-related effects of diuretics in hypertensive subjects

Although the literature on diuretic therapy for essential hypertension is abundant, little attention has been directed to age-related responses, and dose-response information in young compared to elderly patients is lacking. The pharmacokinetic characteristics of some diuretics are modified in the elderly, and these appear to be accounted for by an age-related decline in renal function. Whereas some studies have suggested that the antihypertensive effect of diuretics is enhanced in the elderly, the few "satisfactory" trials available have not confirmed earlier observations. Contrary to first impressions, symptomatic side effects with diuretics are not more frequent in older patients and some trials suggest they are less frequent than in younger hypertensive subjects. Of the biochemical changes induced by diuretics, azotemia, hyponatremia and perhaps hypokalemia appear more frequently in the elderly. The elderly, especially those with underlying cardiac disease, may be more susceptible to the arrhythmogenic effect of diuretics than healthy younger patients, but the evidence is suggestive rather than definitive. It was concluded from this survey of the literature that our knowledge of the age-related effects of diuretics in the treatment of essential hypertension is fragmentary and far from complete.