The treatment of severe hypertension with trandolapril, verapamil, and hydrochlorothiazide. Trandolapril/Verapamil Multicenter Study Group

A multiple drug regimen consisting of trandolapril, verapamil and hydrochlorothiazide (HCTZ) were sequentially added in an open-label evaluation of patients with severe hypertension. Ninety patients (58 white and 32 black patients) were titrated on one or more drugs and followed for a 19-week maintenance period. Statistically significant (P = 0.001) mean (+/-s.d.) decreases in supine diastolic blood pressure (DBP) were 9.0 (+/-9.3) mm Hg for trandolapril, 13.9 (+/-11.0) mm Hg for the trandolapril + verapamil (TV) combination, and 19.0 (+/-12.3) mm Hg when hydrochlorothiazide was added to the combination. The decrease in BP observed on TV combination therapy plus HCTZ was significantly (P = 0.001) greater than the decrease observed for the TV combination, which was significantly (P = 0.001) greater than the decrease observed for trandolapril monotherapy. Clinical responder rates were 44.8%, 56% and 77.7% for trandolapril monotherapy, trandolapril + verapamil combination therapy and triple therapy, respectively. Black and white patients had similar response rates, but black patients appeared to benefit more from the addition of HCTZ; 20% of black patients achieved a post-treatment supine DBP <90 mm Hg compared to 12.8% of white patients. This study demonstrates that the addition of verapamil to trandolapril has an additive effect on BP that is maintained throughout the day.