Combination treatment with telmisartan and hydrochlorothiazide in black patients with mild to moderate hypertension

Background: Hydrochlorothiazide (HCTZ) is commonly used to treat black patients with hypertension. To avoid the metabolic disturbances associated with high-dose HCTZ, blood pressure control may be achieved by combining low doses with another antihypertensive. Hypothesis: The study was undertaken to assess the tolerability and antihypertensive dose-response efficacy of telmisartan and HCTZ and their combination in black patients with mild to moderate hypertension (mean supine blood pressure 140/95-200/114 mmHg). Methods: Following a 4-week, single-blind, placebo run-in period, 222 black patients were randomized to once-daily treatment with one of 20 different double-blind combinations of telmisartan (0, 20, 40, 80, 160 mg) and HCTZ (0, 6.25, 12.5, 25 mg) for 8 weeks. Blood pressure was measured at baseline and after 2, 4, and 8 weeks. Results: Telmisartan 80 mg/HCTZ 12.5 mg reduced supine trough diastolic blood pressure (DBP) - primary efficacy parameter - by 13.3 mmHg, and supine trough systolic blood pressure (SBP) by 21.5 mmHg. These reductions represented benefits of 13.7/8.7 mmHg over telmisartan 80 mg and 12.3/8.1 mmHg over HCTZ 12.5 mg (p < 0.01). Telmisartan 40 mg/HCTZ 12.5 mg reduced supine trough SBP/DBP by 14.3/10.0 mmHg, amounting to 12.3/3.3 mmHg more than telmisartan 40 mg and 5.1/4.8 mmHg more than HCTZ 12.5 mg. This reached significance for the comparisons with telmisartan 40 mg for SBP and HCTZ 12.5 mg for DBP (p ≤ 0.05). A response surface analysis and therapeutic response rates confirmed the additive antihypertensive effects of telmisartan and HCTZ. All treatments were well tolerated, with side-effect profiles comparable with placebo. Adverse events were mainly transient and of mild to moderate severity. Conclusions: Telmisartan 80 mg combined with HCTZ 12.5 mg is effective and well tolerated in black patients with mild to moderate hypertension, providing greater antihypertensive activity than the corresponding monotherapies.