Antihypertensive effects of valsartan/hydrochlorothiazide combination in essential hypertension

Fixed-dose combination therapy has received increased interest since publication of JNC-VI report and WHO/ISH guidelines 1999. We compared in a randomized, double-blind study the efficacy and tolerability of valsartan 80 mg combined with hydrochlorothiazide (HCTZ) 12.5 mg to monotherapy with either HCTZ 12.5 mg or 25 mg in patients with essential hypertension inadequately controlled by previous HCTZ 12.5 mg monotherapy. Two hundred and seventeen patients whose blood pressure (BP) control remained poor (95 mmHg < or = sitting diastolic BP < 115 mmHg) after a 4-week single-blind period with HCTZ 12.5 mg were randomized to receive either combination therapy with valsartan 80 mg plus HCTZ 12.5 mg (V/HCTZ) or monotherapy with HCTZ 12.5 mg or HCTZ 25 mg for 8 weeks. Reduction of sitting trough diastolic BP between baseline and week 8 as well as tolerability was evaluated. Reduction in trough diastolic BP was most pronounced in the V/HCTZ group (-11.3 mmHg) and significantly greater than in the HCTZ 12.5 mg group (-2.9 mmHg, p < 0.001) and the HCTZ 25 mg group (-5.7 mmHg, p < 0.001). Tolerability of study medication was comparable between all three groups. In conclusion, switching to V/HCTZ combination therapy provides an additional lowering of BP compared to dosage increase of the thiazide in patients with BP insufficiently controlled by HCTZ 12.5 mg monotherapy.