May enhance the effect of neuromuscular blockers. Reduced the effect of levodopa. Reduced the activity of altretamine. Decreased serum conc of phenobarb & phenytoin. Hydralazine, INH, penicillamine & OCs. May increase the requirement for pyridoxine. Parenteral chloramphenicol may attenuate vit B12
in anemia. Oral: Absorption may be reduced w/ neomycin, aminosalicylic acid, histamine H2
-antagonists & colchicine. Serum conc may be decreased by OCs.