Diltiazem compared with metoprolol as add-on-therapies to diuretics in hypertension. Swedish Diltiazem-Metoprolol Multicentre Study Group

Abstract

In a randomized, double-blind, parallel group study, diltiazem was compared with metoprolol as add-on therapy to diuretic treatment in 115 patients with hypertension. Following a placebo and diuretic period of four weeks, patients were randomized to either slow release diltiazem 90 mg twice daily or metoprolol 100 mg once daily using a double dummy technique. If after four weeks a target supine diastolic blood pressure (DBP) less than or equal to 90 mmHg pressure was not reached, the doses of diltiazem and metoprolol were doubled. Supine inclusion systolic/diastolic blood pressures (SBP/DBP) at randomization were 158 +/- 13 (mean +/- SD)/102 +/- 5 mmHg in the diltiazem group and 158 +/- 17/101 +/- 6 mmHg in the metoprolol group. Active therapy significantly lowered SBP and DBP in both groups by 7-10%. Heart rate was significantly lowered in both groups, although the effect of metoprolol was more pronounced. Response rates (supine DBP less than or equal to 90 mmHg and/or decreased by greater than or equal to 10%) were 43% on diltiazem 90 mg twice daily and 52% on metoprolol 100 mg once daily, increasing to 82% and 62%, respectively, after dose escalations. No serious side effects were seen, but three patients, two on diltiazem and one on metoprolol, were withdrawn from the study due to severe headache, nausea and bradycardia respectively. of mild to moderate adverse reactions, tiredness was most frequent, occurring in 14.5% and 15.8% on active diltiazem and metoprolol therapy, respectively. We conclude that both diltiazem and metoprolol lower BP when added to diuretics in hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)