An Appraisal of 1, 1-dimethyl-biguanide Treatment for Diabetics Based on Changes in Blood Lactate Levels

Because of the strong clinical side effect of phenformin such as lactic acidosis, we have used 1, 1-dimethyl-biguanide (metformin) as biguanide for the treatment of diabetes mellitus.Since the relation between biguanide and lactic acidosis has been posed as a social problem, we have examined blood lactate levels, arterial pH and anion gap in thirty-two diabetics with a long-term administration of metformin, during the therapy and after the withdrawal of metformin. By the use of metformin, rises of blood lactate levels and anion gap, as well as a significant reduction of arterial pH were observed. However, those changes could be reversed to normal range at two months after the withdrawal of metformin. It is concluded that, although there may exist unavoidable side effect by the administration of metformin in diabetics, and it requires careful examination of blood lactate levels, anion gap and arterial pH during the therapy, the agent should not still be aban doned on the therapy of some diabetics who can not be satisfactorily controlled by other therapy at the present time.