Reactions 1428 - 17 Nov 2012

O SCarbamazepine overdose

Hearing loss and other toxicities: case reportA 43-year-old man developed hearing loss and other

toxicities after overdose of carbamazepine [Tegretal],which he was taking for epilepsy.

The man was hospitalised with hearing loss anddizziness for the past 4 hours. Pure-tone audiometrydetected a sensorineural deafness in the left ear up to 70dB.In the right ear, bone conduction was pantonally about20dB. He was known to have epilepsy, for which he wasreceiving carbamazepine 400mg four times a day [routeand duration of therapy before reaction onset not stated].

The man was diagnosed with acute hearing loss, andgiven cortisone. His dizziness improved the following day,but his hearing loss persisted. Shortly before a plannedtympanoscopy under local anaesthesia, his conditiondeteriorated, with nausea, vertigo and intermittentconfabulation. Frenzel goggles demonstrated rapiddownbeat nystagmus. Ataxia, unsteady gait and tremor ofthe neck muscles were also observed. His serumcarbamazepine level was elevated, at 16.1 mg/L. Aftercarbamazepine had been stopped for 1 day his conditionimproved. His dizziness and nystagmus resolved, and hereported better hearing. Pure-tone audiometry revealed anincrease in bone conduction in the left ear by up to 55dB,with persisting high-tone deafness from 3kHz. An almostpantonal increase of bone conduction by 10dB was notedfor the right ear. He was diagnosed with a carbamazepineoverdose [details of overdose not clearly stated], andtransferred to a neurological ward to stabilise his epilepsy.

Author comment: As shown in the case study,carbamazepine can cause acute hearing losses withoculomotor pathologies.Teudt I, et al. The different hearing loss--easily curable! Laryngo-Rhino-Otologie91: 187-8, No. 3, 2012 [German; summarised from an English translation] -Germany 803079793

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Reactions 17 Nov 2012 No. 14280114-9954/10/1428-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved