Double-blind parallel study of a combination of chlorthalidone 50 mg and triamterene 50 mg in patients with mild and moderate hypertension.

In a double-blind, partial cross-over study of 141 patients with mild to moderate hypertension, chlorthalidone 50 mg was compared with chlorthalidone 50 mg/triamterene 50 mg combination treatment. The study assessed clinical efficacy in the reduction of blood pressure, and safety with regard to serum potassium concentration and adverse reactions. Both treatment regimens were found to offer equivalent therapeutic success, but the decrease in serum potassium concentration was significantly less with the combination treatment than with chlorthalidone alone.