RT Journal A1 Ku E, Park J, Vidhun J, Campese V T1 THe case for dual renin-angiotensin system inhibition—reply JF Archives of Internal Medicine JO Archives of Internal Medicine YR 2009 FD November 9 VO 169 IS 20 SP 1931 OP 1931 DO 10.1001/archinternmed.2009.407 UL http://dx.doi.org/10.1001/archinternmed.2009.407 AB Dr Hirsh raises some interesting points pertaining to our article on dual RAS.1 We agree with Dr Hirsh that the data from the ONTARGET2 trial do not address the issue of patients with proteinuria more than 1 g/d and should not be interpreted to completely dismiss these combinations. However, the available evidence shows that combination therapy with RAS inhibitors is more effective than single RAS blockade in reducing proteinuria, but there is no good evidence that these combinations are more effective than single RAS blockade when it comes to reducing chronic kidney disease progression. The ONTARGET trial should serve as a cautionary reminder that what is expected does not always translate into reality, and further studies are needed before combination therapy are routinely implemented in the treatment of chronic kidney disease.