A randomized, comparative study evaluating the efficacy and tolerability of losartan-low dose chlorthalidone (6.25 mg) combination with losartan-hydrochlorothiazide (12.5 mg) combination in Indian patients with mild-to-moderate essential hypertension

Abstract

Objective: The relationship of blood pressure (BP) to cardiovascular risk is linear, positive, and continuous. Lowering elevated BP reduces the risk of cardiovascular events. The primary objective of this randomized, multicenter, comparative, 3-month, open-label study was to evaluate the antihypertensive efficacy of losartan/chlorthalidone versus losartan/hydrochlorothiazide in mild-to-moderate essential hypertension. Methods: A total of 137 eligible patients underwent a 2-week placebo washout period, following which 131 patients were randomized to losartan (L) 25mg/chlorthalidone (C) 6.25 mg (66/131) or to losartan 25 mg/hydrochlorothiazide (H) 12.5 mg (65/131) at three centers. Patients not responding after 4 weeks of therapy were escalated to losartan 25 mg/chlorthalidone 12.5 mg and losartan 50 mg/hydrochlorothiazide 12.5 mg, respectively. Results: Both treatment groups were similar with respect to demography and baseline characteristics. Altogether, 120 patients completed the study. After 4 weeks of therapy, both treatments showed a significant fall from baseline in systolic BP (SBP) and diastolic BP (DBP) (L/C: -20.17/-10.30; L/H: -17.63/-10.20). Both treatments were similar with respect to mean fall in SBP (p = 0.258), DBP (p = 0.934) and response rate (p = 0.769). Both step-up therapies were similar with respect to mean fall in SBP (p = 0.418), DBP (p = 0.389) from baseline and response rate (p = 0.769). All reported adverse events were of mild-to-moderate intensity, except for two serious AEs that occurred in patients who received L/H. Conclusions: The losartan/low-dose chlorthalidone (6.25 mg) combination is as effective as the widely used losartan/hydrochlorothiazide combination in lowering BP and is well tolerated, thus providing a useful therapeutic option for treating mild-to-moderate hypertension.

Keywords::

• angiotensin receptor blockers (ARBs)
• chlorthalidone
• essential hypertension
• hydrochlorothiazide
• losartan

Acknowledgements

The authors would like to thank Shruti Kulkarni for technical assistance right from the inception of the study and Mitesh Sharma, biostatistician, for statistical analysis and data management for this study.

The abstract of this article has been accepted for poster presentation and was presented in Jackson Cardiovascular-Renal Meeting 2008 organized by the Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi.