Beneficial Effects of High-dose Losartan in IgA Nephritis

Aim: Several short-term studies have reported the efficacy of high-dose ARB in reducing proteinuria in patients with diabetic nephropathy. The benefits of long-term high-dose ARB losartan in IgA nephritis have not been explored.

Method: This was a 6-year randomized trial in 207 patients with IgA nephritis comparing high-dose ARB (losartan 200 mg/day) with normal dose ARB (losartan 100 mg/day), normal dose ACEI (20 mg/day) and low-dose ACEI (10 mg/day). Multivariate ANOVA was used to test the effect of drug treatment on both eGFR and total urinary protein (TUP).

Results: Comparing patients on high-dose ARB (n = 63) with those on normal dose ARB (n = 43), normal dose ACEI (n = 61) and low-dose ACEI (n = 40), patients on high Dose ARB had significantly higher eGFR (p < 0.0005) and lower proteinuria (p < 0.005) at the end of the study. The loss in eGFR was 0.7 ml/min/year for high-dose ARB compared to 3.2 - 3.5 ml/ min/year for the other 3 groups (p = 0.0005). There were more patients on high-dose ARB with improvement in eGFR compared to other 3 groups (p < 0.001).

Conclusion: Data from this study suggest that high-dose ARB therapy is more efficacious in reducing proteinuria and preserving renal function when compared with normal dose ARB and ACEI. In Year 5, patients on high-dose ARB had a gain in eGFR suggesting that there is possibility of recovery of renal function in these patients on long-term high-dose therapy.