[Gait instability revealing a syndrome of inappropriate antidiuretic hormone secretion associated to pregabalin].

Pregabalin, a molecule with similar structure of GABA neurotransmitter, initially developed as an antiepileptic, is now commonly used in the treatment of painful peripheral neuropathies. We report an 82-year-old man who presented with confusion, urinary incontinence and gait instability. He was receiving pregabalin for a left L5 radicular pain. Laboratory tests at admission revealed a profound hyponatremia (117 mmol/L) that was corrected by fluid restriction and pregabalin withdrawal. According to the patient and laboratory outcome, we established the diagnosis of inappropriate antidiuretic hormone secretion due to pregabalin. The test of Naranjo demonstrated a probable imputability of pregabalin.