Chlorthalidone Alone or in Fixed Combination with Slow-Release Metoprolol in the Management of Arterial Hypertension: A Long-Term Study of 545 Patients

In a double-blind trial, 545 out-patients with essential hypertension received 25 mg/day chlorthalidone alone (274 patients) or in fixed combination with 200 mg/day slow-release metoprolol (271 patients) for 8 weeks. Both treatments significantly (P less than 0.001) decreased systolic and diastolic blood pressure; 45.6% of patients receiving chlorthalidone and 82.5% receiving combined therapy had a diastolic blood pressure of less than 95 mmHg. Patients not controlled by chlorthalidone or chlorthalidone plus metoprolol subsequently received chlorthalidone plus metoprolol (137 patients) or chlorthalidone plus metoprolol plus a third drug (34 patients), respectively, for 8 weeks. A total of 79.5% of patients receiving chlorthalidone plus metoprolol and 61.8% receiving chlorthalidone plus metoprolol plus a third drug had a diastolic blood pressure of less than 95 mmHg. Only 5.9% of patients experienced mild to moderate side-effects. Plasma potassium levels significantly (P less than 0.01) decreased during the first 8 weeks only. It is concluded that a diuretic alone or in fixed combination with a beta-blocker is effective in the long-term treatment of arterial hypertension.