Lalau JD, et al. - Researchers carried out this study to define a safe, effective dose regimen for metformin in moderate and severe chronic kidney disease (CKD; stages 3A/3B and 4, respectively), after the lifting of restrictions on metformin use in patients with diabetes with moderate-to-severe CKD in the absence of prospective safety and efficacy studies. Metformin treatment appeared to be safe, provided that the dose was adjusted for renal function. It was found to be pharmacologically efficacious in moderate-to-severe CKD.