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 ⩽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.