Background: Angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers decrease postdiarrheal hemolytic uremic syndrome (D + HUS) sequelar proteinuria. However, proteinuria may persist in some patients. In nephropathies other than D + HUS, an additive antiproteinuric effect with coadministration of both drugs has been observed.
Methods: To assess such an effect in D + HUS, 17 proteinuric children were retrospectively studied. After a median period of 1 year post-acute stage (range 0.5-1.9) patients received enalapril alone for a median of 2.6 years (range 0.33-12.0) at a median dose of 0.4 mg/kg/day (range 0.2-0.56). As proteinuria persisted, losartan was added at a median dose of 1.0 mg/kg/day (range 0.5-1.5) during 2.1 years (range 0.5-5.0).
Results: The decrease in proteinuria with enalapril was 58.0 %, which was further reduced to 83.8 % from the initial value after losartan introduction. The percentage of reduction was significantly greater with the association of both drugs (p = 0.0006) compared with the effect of enalapril exclusively (p = 0.023). Serum potassium, glomerular filtration rate, and blood pressure remained unchanged.
Conclusions: Our results suggest that adding losartan to persisting proteinuric D + HUS children already on enalapril is safe and reduces proteinuria more effectively. Whereas this effect is associated with long-term kidney protection, it should be determined by prospective controlled studies.