Administration of metformin in renal transplant patients with post-transplant diabetes mellitus

Diabetes is the most common cause of renal failure which is frequently seen in candidates of solid organ transplant both before and after of the transplantation. For successful long-term tissue graft, it is important to control blood glucose level particularly after transplantation. Post-transplant diabetes mellitus (PTDM) is the main issue contributing to cardiovascular-related mortality in kidney transplant recipients. Important risk factors of PTDM include using immunosuppressive drugs, post-transplant weight gain and obesity, and the presence of pre-transplant diabetes. Because of safety concerns, there has been a consensus from 2003 onward to cease metformin as the first-line anti-diabetic drug in patients with PTDM. The relationship between PTDM and metformin administration in high-risk renal transplant patients needs to be validated by more trial studies to establish the risk-benefit balance using this drug. Here, we reviewed the pros and cons of using metformin by presenting conclusions from several retrospective and clinical trial studies.