Vit B
6: May increase pyridoxine level which could induce sensory neuropathy w/ nitrofurantoin. High daily doses can decrease phenytoin & phenobarb serum conc. Reduced effectiveness of altretamine (hexamethylmelamine). Reduced or abolished effect of levodopa through increased peripheral metabolism by dopa-decarboxylase. May reduce plasma levels w/ INH. Vit B
12: Reduced intestinal absorption w/ colchicine, aspirin, PPIs & H
2-receptor antagonists. May induce deficiency w/ prolonged metformin use. May lower serum levels most likely due to redistribution rather than depletion w/ contraceptive use. Vit E: May enhance effect of warfarin & aspirin. May decrease oral cyclosporine levels. May reduce plasma conc w/ statin. May reduce intestinal absorption by inhibition of GI lipase w/ orlistat.
Sign Out
