Reduced effect of L-dopa when in concomitant w/ vit B6
. Decreased efficacy of vit B6
w/ pyridoxine antagonists eg, INH, cycloserine, penicillamine, hydralazine. Reduced blood level of vit B1
w/ loop diuretics eg, furosemide. Vit B12
deficiency w/ long-term use of acid lowering agents. Potentiated effect of oral anticoagulant (eg, warfarin). Risk of paracetamol toxicity w/ other potentially hepatotoxic drugs or drugs that induce liver microsomal enzymes (eg, antiepileptics). Decreased effectiveness of lamotrigine. Hepatotoxicity w/ alcohol.