Possible Interaction: Metformin and Thiamine

“Furthermore, metformin as well as other drugs including phenformin, chloroquine, verapamil, famotidine, and amprolium inhibited hTHTR-2 mediated uptake of both thiamine and metformin.”

“In vivo, Oct1 deficiency resulted in substantially reduced intestinal and liver levels of thiamine; similarly, metformin treatment resulted in reduced intestinal and systemic plasma levels of thiamine and a trend toward reduced liver levels of thiamine.”

“Modulation of thiamine levels by metformin (via OCT1 and perhaps other thiamine transporters) may be critically important in its beneficial effects on diabetes, hepatic steatosis, obesity and cancer.”

“Moreover, we observed that metformin competitively inhibited OCT1-mediated thiamine uptake in transfected cells.”

“Acute administration of metformin to wild-type mice reduced intestinal accumulation of thiamine.”

“Collectively, our results point to an important role of thiamine (through OCT1) in hepatic steatosis and suggest that the modulation of thiamine disposition by metformin may contribute to its pharmacologic effects.”