Telmisartan vs losartan plus hydrochlorothiazide in the treatment of mild-to-moderate essential hypertension--a randomised ABPM study.

The objective of this prospective, randomised, open-label, blinded-end point parallel-group, multicentre study was to show that telmisartan 80 mg is not inferior to a fixed-dose combination of losartan 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg in patients with mild-to-moderate hypertension. The criterion for noninferiority was a treatment difference of < or =3.0 mmHg in the reduction of 24-h mean ambulatory diastolic blood pressure (DBP) from the end of the 4-week placebo washout period to the end of the 6-week active treatment period. In the intent-to-treat analysis, the mean reduction in 24-h DBP was 8.3+/-6.7 mmHg among telmisartan-treated patients (n=332) and 10.3+/-6.3 mmHg among losartan/HCTZ-treated patients (n=350). The mean adjusted difference in 24-h DBP between the two treatment groups was 1.9 mmHg, allowing rejection of the a priori null hypothesis of a treatment difference of >3 mmHg. The reduction in mean 24-h systolic blood pressure was 13.2+/-10.2 mmHg with telmisartan and 17.1+/-10.3 mmHg with losartan/HCTZ. Both drugs provided effective control over the 24-h dosing interval. Analyses of morning (0600-1159) ambulatory blood pressure monitoring DBP means and trough cuff DBP confirmed the noninferiority hypothesis of the protocol for telmisartan 80 mg vs losartan 50 mg/HCTZ 12.5 mg. The reductions in office blood pressures measured at trough in patients treated with telmisartan were -16.3/-9.6 and -18.5/-11.1 mmHg in the patients treated with losartan/HCTZ (difference -2.4/-1.2 mmHg). There were no differences between the side-effect profiles of the two treatments.