Thrombocytopenia induced by diazoxide in a patient with an insulinoma.

A 24-year-old healthy woman presented at our hospital due to hypoglycemia. A fasting test provoked spontaneous hypoglycemia, and contrast-enhanced abdominal computed tomography revealed a pancreatic tumor. We diagnosed her with insulinoma and initiated diazoxide treatment to prevent hypoglycemia. After 13 days of treatment, she experienced nasal bleeding, and her platelet count decreased from 186,000 /μL to 28,000 /μL. The thrombocytopenia was ameliorated five days after diazoxide was discontinued. Although diazoxide has hyperglycemic effects associated with decreased insulin secretion, diazoxide-induced thrombocytopenia is rare. A complete blood count should be obtained periodically in patients receiving treatment with diazoxide.