Objectives: To investigate the efficacy and tolerability of valsartan (Val) 320 mg once daily (o.d.), Val/hydrochlorothiazide (HCTZ) 320/12.5 mg o.d. and Val/HCTZ 320/25 mg o.d. in patients with hypertension not adequately controlled by Val monotherapy.
Methods: This double-blind, active-controlled, parallel-group, randomized trial recruited patients > or =18 years with mild-to-moderate essential hypertension, defined as mean sitting diastolic blood pressure (MSDBP) of > or =95 mmHg and <110 mmHg without treatment. After washout, 3805 eligible patients received Val 320 mg o.d. single-blind for 4 weeks. Subsequently, patients with MSDBP > or =90 and <110 mmHg (n=2702) were randomized to double-blind treatment with Val 320 mg, Val/HCTZ 320/12.5 mg or Val/HCTZ 320/25 mg for 8 weeks. Mean changes in MSDBP and mean sitting systolic BP (MSSBP) from the start of the single-blind period were analysed, as well as the proportion of responders (MSDBP <90 mmHg or > or =10 mmHg decrease from the start of the double-blind period). Tolerability and safety were also assessed.
Results: Reductions in MSDBP and MSSBP were observed in all groups. Both combinations were associated with significantly greater reductions than monotherapy for MSDBP and MSSBP at Weeks 8 and 12 (all p<0.0001). Both combinations also resulted in significantly greater proportion of responders at study end (74.9% and 68.8% for Val/HCTZ 320/25 mg and Val/HCTZ 320/12.5 mg, respectively) than monotherapy (52.7%; both p < 0.0001). In addition, a dose-response was observed with increasing dose of HCTZ with respect to MSSBP. All treatments were well tolerated.
Conclusions: The combination ofVal and HCTZ at doses of 320/12.5 mg and 320/25 mg increases antihypertensive efficacy in patients with mild-to-moderate hypertension inadequately controlled with Val 320 mg monotherapy, without compromising tolerability.