[Tramadol-induced hypoglycemia. 2 cases].

INTRODUCTION: Tramadol has been approved in France since 1994 for the treatment of moderate to severe pain. The most commonly reported adverse effects involve the central nervous system and gastrointestinal tract. To our knowledge, hypoglycemia has not previously been reported. CASE: We report 2 cases of hypoglycemia related to tramadol, one in a nondiabetic 88-year-old woman, and the other in a diabetic 8-year-old girl. Hypoglycemia resolved after tramadol discontinuation. DISCUSSION: The French Pharmacovigilance (Adverse Drug Reports) database includes several cases of hypoglycemia in patients receiving tramadol. Reports from the literature of dextropropoxyphene-induced hypoglycemia and a pharmacological study of tramadol in rats suggest that the micro opioid receptor is the principal target involved in this hypoglycemic mechanism.