Phenethylbiguanide (DBI) has been used for its hypoglycemic action in the treatment of diabetes mellitus in 206 patients for a period of two years. Adequacy of management, maintained in 128 patients, was judged by the absence of diabetic symptoms and of the drug's side-effects (nausea, anorexia, and gastrointestinal disturbances). DBI made exogenous insulin unnecessary in 110 patients who were known to have a partial supply of insulin from their pancreas. The exogenous insulin requirement was decreased one-half when 18 patients who produced no natural insulin were given DBI. Severe gastrointestinal intolerance to DBI forced 53 patients to stop taking it, but recovery from untoward effects was complete in every case. During the two-year administration there were no signs or symptoms in any of the 206 patients indicative of tissue damage due to DBI.
Pomeranze J, Mouratoff GT, Gadek RJ, King EJ. PHENETHYLBIGUANIDE, A NEW ORALLY GIVEN HYPOGLYCEMIC AGENTREPORT AFTER TWO YEARS OF CLINICAL EXPERIENCE. JAMA. 1959;171(3):252-258. doi:10.1001/jama.1959.03010210004002