CONCOMITANTLY USE WITH OTHER DRUGS THAT LOWER BLOOD SUGAR CONCENTRATIONS INCREASES THE RISK OF HYPOGLYCAEMIA. ALCOHOL MAY INCREASE THE RISK OF LACTIC ACIDOSIS AS WELL AS HYPOGLYCAEMIA. CIMETIDINE INCREASED THE PLASMA CONCENTRATION OF METFORMIN. KETOTIFEN DECREASE PLATELET COUNTS WHEN GIVEN CONCURRENTLY. AN INCREASED HYPOGLYCAEMIC EFFECT HAS OCCURRED OR MIGHTBE EXPECTED WITH ACE INHIBITORS, ALCOHOL, ALLOPURINOL, AZAPROPAZONE, PHENYLBUTAZONE, AND SALICYLATES, AZOLE ANTIFUNGALS, CHLORAMPHENICOL, CIMETIDINE, CLOFIBRATE, COUMARIN ANTICOAGULANTS, HALOFENATE, HEPARIN, MAOIS, RANITIDINE SULPHINPYRAZONE, TETRACYCLINES, TRICYCLIC ANTIDEPRESSANTS AND THYROID HORMONES.