Thirteen trials (n=4,066 patients) were included in the review. Thirteen trials were randomised parallel-group trials; nine of these trials were described as double-blinded. There were two trials in which 25mg of hydrochlorothiazide were administered to patients in both the candesartan and losartan treatment arms. There were two trials in which two dosage regimens were compared with a single dose of losartan, which meant there were 15 comparisons of candesartan with losartan.
Statistically significant greater reductions in systolic blood pressure were observed with candesartan compared with losartan across all the trials (WMD 3.22mm Hg, 95% CI 2.16 to 4.29).
Significant reductions in systolic blood pressure were also observed when candesartan was compared with losartan in trials in which hydrochlorothiazide was not given (WMD 2.57, 95% CI 1.71 to 3.44; 11 monotherapy trials; n=3,607 patients), when low-dose candesartan (4mg and 8mg) was compared with low-dose losartan (25mg and 50mg) (WMD 2.74, 95% CI 0.83 to 4.64; four trials; n=588 patients), when high-dose candesartan (12, 16 and 32mg) was compared with high-dose losartan (100mg) (WMD 2.49, 95% CI 1.52 to 3.47; eight trials; n=2,852 patients), and when candesartan and losartan were each administered with 25mg of hydrochlorothiazide (WMD 7.03, 95% CI 4.26 to 9.80; two trials; n=459 patients).
Diastolic blood pressure was also significantly reduced with candesartan treatment compared with losartan (WMD 2.21 mm Hg, 95% CI 1.34 to 3.07) across all the trials. This pattern of reduction was observed in the monotherapy trials and for the comparisons of low-dose and high-dose treatments.
There was no statistically significant heterogeneity reported across the trials for any of the outcomes evaluated.