Double-blind trial of antihypertensive effect of chlorothiazide in severe renal failure

A randomised double-blind crossover trial was done to assess the efficacy of chlorothiazide as an antihypertensive drug in patients with severe renal failure. There was a significant reduction in standing (mean drop 13/6 mm Hg) and supine (mean drop 13/5 mm Hg) blood-pressure, without postural hypotension. Chlorothiazide has a place in the management of hypertension in patients with severe renal failure and its antihypertensive effect is probably due to a change in peripheral vascular resistance and not to volume contraction.