Safety and efficacy of a three-drug regimen for the treatment of hypertension: hydrochlorothiazide, propranolol, and guanadrel.

Twenty-seven patients with moderate to moderately severe hypertension who had not responded optimally to treatment with a standard step 2 regimen were treated with a three-drug regimen of hydrochlorothiazide, propranolol, and guanadrel. The addition of guanadrel reduced blood pressure to levels significantly below those achieved by the step 2 regimen. The achievement of normotensive blood pressure levels was accompanied by a decrease in the number of adverse effects reported.