OBJECTIVETo evaluate the efficacy and safety of a fixed dose combination of telmisartan 80 mg plus hydrochlorothiazide (HCTZ) 12.5 mg (TH) to telmisartan 80 mg (T) in Chinese patients who failed to respond adequately to treatment with T.

METHODThis is a multi-center, randomized, double-blind, double-dummy clinical study. A total of 699 eligible hypertensive patients entered a one-week screening phase prior to the eight-week open-label T period. At the end of eight weeks, 345 patients who failed to respond to T (DBP > or = 90 mm Hg, 1 mm Hg = 0.133 kPa) were randomized to receive either TH (175 patients) or T (170 patients) for another eight weeks. Sitting and standing BP were taken 24 hours post-dose and adverse events were documented at visit with 4 weeks interval. Laboratory, ECG and physical examination were performed at screening, at baseline and at the final visit.

RESULTSAfter 8 weeks treatment, (1) The mean trough reduction in sitting diastolic blood pressure (SiDBP) from baseline in TH group was greater than that in T group (10.1 mm Hg vs 7.7 mm Hg, P = 0.0017). The mean trough reduction in sitting systolic blood pressure (SiSBP) from baseline was 14.2 mm Hg in TH group and 7.4 mm Hg in T group (P < 0.0001). (2) The mean trough reduction in standing DBP and standing SBP from baseline were significantly greater in TH group (8.7 mm Hg and 12.9 mm Hg) compared those in T group (7.3 mm Hg and 7.0 mmHg, P = 0.0350, P < 0.0001). (3) The number and percentage of responders in TH group (129, 74.6%) were significantly higher than in T group (100, 59.2%, P = 0.0016). (4) The incidence of the study drug-related adverse events was similar between TH and T group (3.5% vs. 3.6%, P > 0.05).

CONCLUSIONTH was more effective than T in patients not responded adequately to T in Chinese hypertensive patients.