Propanolol-Induced Somnambulism: An Ignored Adverse Effect?

Abstract

We present a 24-year-old male patient with a history of episod-ic migraine without aura since age 12. He was initially medicated with topiramate, but due to adverse effects, a switch was made to propranolol with a gradual increase to 40 mg twice a day. Despite an improvement in the frequency, duration, and intensity of the headache crisis, 2 weeks after starting this therapy, the patient started having nocturnal episodes, every week, characterized by wandering around the house and carrying out purposeless ev-eryday tasks, with minimal interaction, lasting several minutes. The patient reported occasional soliloquies, but without a previous history of somnambulism or other sleep parasomnias, par-ticularly in childhood, but with a positive family history of sleepwalking (brother). A diagnosis of somnambulism induced by propranolol was made. The patient stopped gradually the propranolol and started amitriptyline until 25 mg/day, with the resolution of the sleepwalking and good control of his migraine. In this report, the patient had no history of somnambulism, al-though positive familiar history. He experienced episodes of sleepwalking 15 days after starting propranolol until 40 mg bid. The symptoms completely disappeared after the withdrawal of propranolol. In the literature, there are 5 more cases of somnambulism related to propranolol [1-3]. All patients were female (age range: 24–61 years old), with propranolol doses between 20–120 mg/day. In one of them, propranolol was added with another drug (olanzapine). In 3 of the patients, there was a history of somnambulism. The onset of sleepwalking ranged from 1–33 days after