The effects of two combinations of a beta-blocker and a diuretic on diuresis in normal subjects.
Combinations of a beta-blocker and a diuretic often produce a greater fall in blood pressure than does either drug alone. Furthermore, beta-blockers prevent an increase in plasma renin activity, thereby attenuating diuretic-induced potassium excretion and also the reduction in hypotensive response to the diuretic. This study was designed to compare the effects of the two fixed-dose combinations atenolol 100 mg plus chlorthalidone 25 mg (Tenoretic; ICI) and sotalol 320 mg plus hydrochlorothiazide 50 mg (Sotazide; B-M) on the pattern of diuresis and the biochemical composition of the urine in normal subjects. These preparations differ mainly in that the plasma half-lives of chlorthalidone and hydrochlorothiazide are 60 hours and 6 hours respectively; the former therefore accumulates when given once daily while the latter does not. These two preparations were found to have similar effects on the pattern of diuresis and the biochemical values. It is therefore concluded that the relationship between the serum chlorthalidone level and the fall in serum potassium level is in keeping with the flat dose-response curves for the thiazide and phthalimide diuretics.
D000328:Adult; D001262:Atenolol / Q000008:administration & dosage*; D002752:Chlorthalidone / Q000008:administration & dosage*; D002986:Clinical Trials as Topic; D004231:Diuresis / Q000187:drug effects*; D004359:Drug Therapy, Combination; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage*; D008297:Male; D011188:Potassium / Q000097:blood / Q000652:urine; D012964:Sodium / Q000652:urine; D013015:Sotalol / Q000008:administration & dosage*; D014527:Uric Acid / Q000097:blood; D014556:Urine / Q000502:physiology
D006852:Hydrochlorothiazide; D014527:Uric Acid; D001262:Atenolol; D012964:Sodium; D013015:Sotalol; D002752:Chlorthalidone; D011188:Potassium