A twelve-year old boy with proven type 1 glycogen storage disease and accompanying hypoglycemia and hyperlipemia was treated with diazoxide. Increase of 30 to 70 mg. per 100 ml. in postprandial plasma glucose levels and decrease in oral glucose tolerance occurred. Skin xanthomata disappeared during diazoxide treatment despite an increase of over 1,700 mg. per 100 ml. in plasma triglycerides. Treatment of the patient had to be discontinued after seventeen days because of a diffuse petechial eruption, presumably due to drug sensitivity.
The mechanism(s) by which hyperglycemia is induced with diazoxide are not yet established. Glycogenolysis would appear to be excluded in this patient by virtue of the enzymatic deficiency present. Inhibition of plasma insulin response to glucose was demonstrated.
Support for a third mechanism is presented, based on analysis of serial oral glucose tolerance tests. It is suggested that diazoxide, directly or indirectly, inhibits hepatic glucose uptake.
