Monitoring Patients on Metformin: Recent Changes andRationales

摘要

>Objective: The Food and Drug Administration recently updated metformin prescribing recommendations for patients with diabetes and renal disease. The American Diabetes Association as well as the American Association of Clinical Endocrinologists and American Clinical Endocrinologists also recommend periodic monitoring of vitamin B12 levels for patients using metformin. A review of the literature was conducted to assess data to evaluate the recent updates to metformin usage and provide rationales for these recommendations. >Data Sources: PubMed MESH terms “Diabetes Mellitus, Type 2” and “Renal Insufficiency, Chronic” and “Metformin” were searched with an English limitation from 1990 to May 2017. A MEDLINE search was conducted using the terms “metformin” and “renal disease” from 1990 to May 2017. A PubMed search was conducted using the MESH terms “vitamin b12 deficiency” and “metformin” from 1970 to May 2017. A MEDLINE search was conducted using terms “metformin” and “vitamin B12 deficiency” with an English limitation from 1970 to May 2017. >Study Selection and Data Extraction: Retrospective and prospective clinical trials, meta-analyses, and systematic reviews were considered for inclusion. Citations from identified articles were also reviewedfor inclusion. >Data Synthesis: The incidence ofmetformin-associated lactic acidosis is minimal. Data indicate metformin-treatedpatients with an estimated glomerular filtration rate above 30 mL/min/1.73m² have a reduction in mortality. Additionally, data suggestmetformin may lead to vitamin B12 deficiency.>Conclusion: Data support recommendations for metformin use inpatients with diabetes and renal insufficiency with an estimated glomerularfiltration rate above 30 mL/min/1.73 m². Data also suggest thatbaseline and periodic testing of vitamin B12 levels are warranted andsupported by clinical guidelines due to the risk of vitamin B12deficiency in metformin-treated patients.