title: Adequacy of twice daily dosing with potassium chloride and spironolactone in thiazide treated hypertensive patients.
abstract: 1. The effects of 4-6 weeks treatment with placebo, potassium chloride 32 mmol 12 hourly, and spironolactone 25 mg 12 hourly upon the plasma potassium concentration-time profile were examined in hypertensive patients taking bendrofluazide 5 mg daily. 2. When compared with placebo, potassium chloride increased peak plasma potassium concentration (P less than 0.05), 12 h AUC for plasma potassium (P less than 0.1), and 12 h urine potassium excretion (P = 0.002). Spironolactone increased peak plasma potassium concentration (P less than 0.05), and 12 h AUC for plasma potassium (P less than 0.05), compared with placebo values. 3. Potassium chloride and spironolactone did not differ significantly in any respect other than 12 h urine potassium excretion. The 12 h AUC for plasma potassium was 35% larger with spironolactone than potassium chloride (not significant). 4. With both active drugs peak plasma potassium was observed 2-3 h after dosing, and efficacy tended to wane towards 12 h. However, variability of plasma potassium within the dose interval was not increased markedly, and 12 hourly dosing is probably satisfactory for both potassium chloride and spironolactone at the doses studied.
authors.affiliation: University Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield.
authors.forename: J M
authors.initials: JM
authors.lastname: Toner
authors.forename: L A
authors.initials: LA
authors.lastname: Brawn
authors.forename: W W
authors.initials: WW
authors.lastname: Yeo
authors.forename: L E
authors.initials: LE
authors.lastname: Ramsay
mesh_terms: D000328:Adult; D000368:Aged; D001539:Bendroflumethiazide / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood / Q000652:urine; D011189:Potassium Chloride / Q000008:administration & dosage* / Q000627:therapeutic use; D013148:Spironolactone / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D013148:Spironolactone; D001539:Bendroflumethiazide; D011189:Potassium Chloride; D011188:Potassium