THE EFFECTS OF DEXTROTHYROXINE IN DIABETES.

Eighteen diabetic patients were treated with dextrothyroxine (from 2 mg to 8 mg daily) for varying periods up to six months. This produced a decided reduction of serum cholesterol levels. Statistically valid comparisons were made of their fasting blood sugar levels before and after two weeks of dextrothyroxine treatment. Administration of this drug was associated with a significant elevation of fasting blood sugar levels. Good diabetic control did not preclude this adverse effect. After more prolonged treatment with the drug, 8 of the 18 patients experienced progressive deterioration of their diabetic control, necessitating increased amounts of insulin or oral drugs. Despite close observation, one patient developed acidosis. When dextrothyroxine was discontinued, there was a significant drop in blood sugar levels in these patients. Two patients had hypoglycemic reaction. When the fasting blood sugar values of the 18 patients, studied while they were receiving significant doses of dextrothyroxine, are compared with a control series of blood sugar determinations obtained on these same patients before dextrothyroxine administration was begun, the diabetogenic effect of this drug is confirmed by the highly significant difference demonstrated. Four patients were given dextrothyroxine a second time, and again experienced deterioration of diabetic control.