Evaluation of the effects of fixed combinations of sustained-release verapamil/trandolapril versus captopril/hydrochlorothiazide on metabolic and electrolyte parameters in patients with essential hypertension

The objective of this randomised open, active controlled, cross-over study was to evaluate the effect of a fixed combination of verapamil SR/trandolapril compared to captopril/hydrochlorothiazide on serum lipids, lipoproteins, and other metabolic and electrolyte parameters in patients with essential hypertension. Another objective was to assess the efficacy and safety of both combinations. One hundred hypertensives with systolic blood pressure 140-209 mm Hg and diastolic blood pressure 90-119 mm Hg were evaluated after 16 weeks receiving a fixed combination of verapamil SR 180 mg/trandolapril 2 mg (VT) or captopril 50 mg/hydrochlorothiazide 25 mg (CH) both given once daily. Lipids and lipoproteins were assessed in duplicate on 2 consecutive days. The study was completed by 80 patients. There was no statistically significant difference between the two combined regimens with respect to low-density lipoprotein (LDL)-cholesterol for the 'intention-to-treat' population measured at the end of each treatment period (3.44 +/- 0.87 mmol/L with VT, and 3.46 +/- 0.86 mmol/L with CH). No differences were found for other lipid parameters like total cholesterol, triglycerides, apolipoproteins A1 and B, Lp(a). High-density lipoprotein (HDL)-cholesterol was significantly higher with VT (1.39 +/- 0.01 vs 1.35 +/- 0.01, P < 0.03). Serum potassium declined while uric acid and glucose increased on CH. In conclusion, no significant differences were found in LDL-cholesterol and in other lipid parameters with the exception of HDL-cholesterol which was significantly higher on VT. Serum potassium declined while uric acid and glucose increased on CH (all significantly). Both fixed combinations were well tolerated. The incidence of adverse events was higher on CH. Both fixed combinations significantly lowered BP.