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JAMA Insights
Clinical Update
April 22, 2019

Metformin in 2019

Author Affiliations
  • 1Endocrinology Service, Division of Subspecialty Medicine, Memorial Sloan Kettering Cancer Center, New York, New York
  • 2Section of Endocrinology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
JAMA. 2019;321(19):1926-1927. doi:10.1001/jama.2019.3805

Metformin is the first-line pharmacologic treatment for type 2 diabetes and the most commonly prescribed drug for this condition worldwide, either alone or in combination with insulin or other glucose-lowering therapies. Metformin is a biguanide, a drug class of herbal origin that has been widely used to treat diabetes since the 1950s.1,2 Two other biguanides were withdrawn from clinical use because they caused lactic acidosis. Metformin was also taken off the US market due to concerns over lactic acidosis, but it subsequently has been proven safe and effective in lowering glucose levels and was reintroduced in 1995. Optimal metformin use requires clear understanding of its effects, dosing, safety, and alternatives.