THE NELSON Committee hearings in the US Senate (Sept 18 to 20, 1974) explored the safety, effectiveness, and use of hypoglycemic drugs. A dozen witnesses, including the Food and Drug Administration (FDA) Commissioner Dr. Alexander Schmidt, gave testimony concerning the implications of the University Group Diabetes Program (UGDP) articles for medical practice. Concern was expressed because the FDA Bureau of Drugs had not required appropriately written package inserts warning physicians and the drug-consuming public of the dangers inherent in the indiscriminate use of sulfonylureas and phenformin hydrochloride. There was agreement that caloric restriction with weight reduction is the preferred method of treatment for the maturity-onset diabetic who is above ideal body weight, and that such therapy is always safe and with intensive education and follow-up is usually effective.
The UGDP investigators ended the tolbutamide (sulfonylurea) study in 1969 and the phenformin study in 1971, when careful statistical analysis showed a death
Davidson JK. The FDA and Hypoglycemic Drugs. JAMA. 1975;232(8):853–855. doi:10.1001/jama.1975.03250080049021