I read with much interest the letter of Dr Alston on the potential relation between metformin-associated lactic acidosis and potential metformin antithiamine activity. It is about a tempting assumption, with a rationale resting on animal data,1- 3 but, to our knowledge, without well-documented human data. This assumption would probably deserve to be tested. However, in clinical practice, among our patients with denutrition and chronic alcohol consummation, often deprived of vitamin B1, we have not observed any lactic acidosis under metformine therapy.
Andrès E, Noel E. Does Metformin Interfere With Thiamine?—Reply. Arch Intern Med. 2003;163(8):983. doi:10.1001/archinte.163.8.983