Possible Role of Roflumilast in Diabetic Nephropathy

Inclusion Criteria: diabetic patients with persistent micro- or macroalbuminuria despite treatment with the maximum tolerated dose of ACE inhibitors for at least 8 weeks before the screening and randomization * Type I or II diabetic patient with stage 2 CKD (eGFR = 60 - 89 ml/min) ,stage 3 CKD (eGFR = 30 - 59 ml/min) or stage 4 (eGFR 15-29 ml/min) Exclusion Criteria: * moderate to severe hepatic disease (Child-Pugh B or C) severe renal disease (eGFR\<15 ml/min) body-mass index below 25 kg/m2 concomitant use of strong cytochrome P450 inducers (e.g. rifampicin, phenobarbital, carbamazepine, phenytoin) known psychiatric illness, congestive heart disease patients with allergy for roflumilast pregnant and lactating women