Rapid onset of syndrome of inappropriate antidiuretic hormone secretion induced by duloxetine in an elderly type 2 diabetic patient with painful diabetic neuropathy

Diabetic neuropathy is the most common diabetic complication. Duloxetine, a serotonin noradrenaline reuptake inhibitor (SNRI), is widely used for the treatment of diabetic painful neuropathy (DPN) because of the efficacy and safety profile. Syndrome of inappropriate antidiuretic hormone secretion, which is strongly associated duloxetine, is a rare but occasionally life-threatening adverse effect. Here, we report a case of syndrome of inappropriate antidiuretic hormone secretion that rapidly developed after starting duloxetine in an elderly Japanese female type 2 diabetes mellitus patient. Furthermore, we discuss the possible relationship between the onset of syndrome of inappropriate antidiuretic hormone secretion and the gene polymorphism of cytochrome P450 isoform 1A2 and 2D6, both of which are responsible for duloxetine metabolism.