Paracetamol: Increased risk of toxicity w/ hepatotoxic drugs or drugs that induce liver microsomal enzymes. Increased absorption w/ metoclopramide. Altered plasma conc & excretion may be affected w/ probenecid. Reduced absorption w/ colestyramine. Vit B
6: Reduces effect of l-dopa. Reduces altretamine activity. Decrease serum conc of phenobarb & phenytoin. May increase requirements for pyridoxine w/ hydralazine, INH, penicillamine & OCs. Vit B
12: Reduced absorption from GI tract w/ neomycin, aminosalicylic acid, H
2-antagonists, omeprazole & colchicine. Decreased serum conc w/ OCs.