Dose adjustment of metformin and dipeptidyl-peptidase IV inhibitors in diabetic patients with renal dysfunction

Objectives: This analysis of real-world data aimed to (a) determine the proportion of Type II diabetes (T2DM) patients treated with metformin or dipeptidyl peptidase-4 inhibitors (DPP-4i) that require dose adjustment or therapy discontinuation due to chronic kidney disease (CKD), and (b) to assess the time required to dose adjustment from the time of worsening of CKD. Methods: In this retrospective study, two study populations were defined in a large healthcare organization. In the cross-sectional analysis, the distribution of CKD stages and the appropriate dosage of metformin and DPP-4i in 2013 was examined according to renal function among T2DM patients. In the longitudinal analysis, a cohort was defined to assess the time elapsed from first indication worsening of CKD to dose adjustment, among patients treated with those medications during years 2006–2013. Results: Among patients treated with metformin or DPP-4i, one third of patients with CKD failed to adjust the dosage or to discontinue metformin or DPP-4i as indicated. Median time for dose adjustment or discontinuation was significantly longer for DPP-4i than for metformin (9.8 compared to 16.8 months for metformin and DPP-4i, respectively; p-value <.001). Conclusions: This real-world data analysis showed that adjustment of dose or discontinuation of metformin or DPP-4i in patients with worsening CKD occurred less often in DPP-4i users than metformin users and took a longer time.