title: Is low-dose hydrochlorothiazide effective?
abstract: In a double-blind crossover study, 13 patients with pretreatment diastolic blood pressure between 95 and 109 mm Hg received nadolol, 80 mg/day, plus placebo of hydrochlorothiazide and nadolol, plus three different doses of active hydrochlorothiazide. Patients remained on each active regimen for 3 weeks, with an intervening placebo period of 2 to 4 weeks. With 12.5 mg of hydrochlorothiazide daily plus nadolol, there was no greater reduction of blood pressure than with nadolol alone. A dose of 25 mg of hydrochlorothiazide was associated with a significantly greater decrease in systolic but not diastolic pressure, as compared with nadolol alone. A significantly greater reduction in both systolic and diastolic blood pressure was obtained only with the 50 mg/day dose of hydrochlorothiazide. Extension to 6 weeks of treatment with 12.5 mg/day failed to lower the blood pressure more than the level seen at 3 weeks. These results suggest that in combination with nadolol, 12.5 mg of hydrochlorothiazide per day has no significant antihypertensive effect. There was no evidence of a flat dose-response curve in the daily dose range of 12.5 to 50 mg. For most patients, a dose of 50 mg of hydrochlorothiazide was required to lower both systolic and diastolic blood pressure significantly below the level obtained with nadolol alone.
mesh_terms: D000070:Acebutolol / Q000008:administration & dosage; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004656:Enalapril / Q000008:administration & dosage; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage* / Q000009:adverse effects; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009248:Nadolol; D011188:Potassium / Q000097:blood; D011412:Propanolamines / Q000008:administration & dosage
chemical_list: D011412:Propanolamines; D006852:Hydrochlorothiazide; D009248:Nadolol; D000070:Acebutolol; D004656:Enalapril; D011188:Potassium