Hypoglycemia associated with fluoxetine treatment in a patient with type 1 diabetes

We report on a patient with type 1 diabetes mellitus who presented with recurrent episodes of hypoglycemia and a marked reduction in her daily insulin requirements after introduction of fluoxetine. This 25-year-old Caucasian woman had been followed up at the outpatient clinic for type 1 diabetes mellitus and pre-pregnancy care. She used a continuous subcutaneous insulin infusion with lispro and her daily insulin dose was 0.5 IU/kg per day. She had no chronic diabetic complications or hypoglycemia unawareness. Fluoxetine at a daily dose of 20 mg had been started because of depressive symptoms and within one week, she presented recurrent hypoglycemic episodes that prompted a progressive reduction in the insulin dose down to 0.3 IU/kg per day. The reduced insulin requirements continued during the period of fluoxetine treatment while glycated hemoglobin remained stable. She had no concurrent additional cause to explain the reduced insulin requirements. After fluoxetine was stopped, insulin requirements progressively increased and returned to the patient´s usual dose.