Carbamazepine and Rebound Mania

Mr. A was a 59-year-old Caucasian man with no personal or family history of mood disorder who was treated for neuropathic pain with carbamazepine at a dose of 1 g/day. His concurrent medications included 10 mg/day of ramipril, 20 mg/day of simvastatin, and 75 mg/day of aspirin. His pain responded well to carbamazepine, but after 18 months, he abruptly stopped this medication without consulting his physician. Four days later, his mood became elevated and irritable, with overactivity and a decreased need for sleep. He did not seek medical attention at this stage, but 3 weeks later, he restarted carbamazepine and returned to euthymia within 10 days.

Eighteen months after this, he again stopped carbamazepine abruptly on the advice of his dermatologist because there were concerns that it may have been exacerbating his psoriasis. Within 3 weeks, his mood again became elevated. He then had several clear features of mania, including overactivity, reduced sleep, social disinhibition, pressured speech, flight of ideas, and several grandiose delusions. His insight was significantly impaired, and he required admission to the hospital under mental health legislation. Carbamazepine was reinstated but this time with no response. Ultimately, he required intensive inpatient treatment over a 5-month period, finally recovering by taking a combination of sodium valproate, 1 g/day, plus olanzapine, 20 mg/day. Olanzapine was discontinued 2 months later, and for the next 4 months, he remained well while taking a maintenance dose of sodium valproate, 1 g/day.