Potential interaction w/ fluorouracil; antibiotics (eg, trimethoprim & sulphonamides); indigestion remedies (edible clay & antacids containing Al or Mg); Zn-containing prep eg, vit or food supplements; cholestyramine; sulfasalazine; triamterene; antiepileptics eg, phenytoin, phenobarb, primidone, Na valproate, carbamazepine, barbiturate; MTX; lithium; aspirin; alcohol; anaesth.