RESUMEN
STUDY DESIGN: An open-label, multicentre study was conducted to evaluate the antihypertensive efficacy of a 4-week course of losartan 50 mg plus hydrochlorothiazide 12.5 mg in Asian patients with essential hypertension whose blood pressure had previously been treated with but not controlled by valsartan 80 mg. METHODS: A total of 237 eligible patients with mean trough sitting diastolic blood pressure (SiDBP) 95-115 mmHg and a mean trough sitting systolic blood pressure (SiSBP) < 190 mmHg entered the baseline period of treatment with valsartan 80 mg/day for 4 weeks. Those (n = 165) whose SiDBP remained > 90 mmHg and who were not excluded for other reasons were then switched to a single-tablet formulation of losartan 50 mg/hydrochlorothiazide 12.5 mg combination once daily for a further 4 weeks. RESULTS: Mean SiDBP (study primary endpoint) at the end of combination therapy was reduced to 86.9 mmHg from 95.2 mmHg. SiSBP (study secondary endpoint) was reduced to 132.6 mmHg from 140.7 mmHg. Mean reductions after switching from valsartan 80 mg to losartan 50 mg/hydrochlorothiazide 12.5 mg were thus 8.3 and 8.1 mmHg for SiDBP and SiSBP, respectively (p < or = 0.001 for both outcomes). The goal of SiDBP < or = 90 mmHg was attained in 72% of the patients previously not controlled to the same level by valsartan 80 mg/day. Combination therapy with losartan 50 mg/hydrochlorothiazide 12.5 mg was generally well tolerated. Mean compliance with the losartan 50 mg/hydrochlorothiazide 12.5 mg combination was > 99%. CONCLUSION: These results demonstrate that in Asian patients who do not reach the goal of mean trough SiDBP < or = 90 mmHg with valsartan monotherapy at 80 mg once-daily, switching to a single-tablet combination of losartan 50 mg/hydrochlorothiazide 12.5 mg once-daily is well tolerated, provides effective control of blood pressure and is an excellent choice to achieve blood pressure reduction goals.