Reactions 1305 - 12 Jun 2010

SCarbamazepine

Seizures secondary to hyponatraemia in anelderly patient: case report

A 74-year-old man developed seizures secondary tohyponatraemia after starting carbamazepine following aninitial seizure episode.

Following admission for aphasia and right hemiparesis, abrain CT revealed an acute ischaemia lesion in the man’stemporal lobe. Around 36 hours postadmission, heexperienced a generalised seizure. An EEG showedaspecific left hemisphere abnormalities and carbamazepine100mg twice daily was started. Concomitant medicationsincluded atorvastatin, clopidogrel, esomeprazole andramipril. Although his presenting symptoms had greatlyimproved 10 days postadmission, he had episodes ofdrowsiness, gait instability, slurred speech, absences andurine loss. Laboratory testing revealed mild hyponatraemia(124 mEq/L). During post-stroke rehabilitation, heexperienced seizures at an increasing frequency [durationof therapy before reaction not stated] and hiscarbamazepine dosage was increased to 200mg twicedaily, without benefit. A repeat EEG showed diffuse slowingdischarges with no evident epileptic signs, while repeattesting revealed a sodium level of 117 mEq/L.

Carbamazepine was discontinued and the man’shyponatraemia resolved. Thereafter, he received no furtherantiepileptic medication and had no more seizures.

Author comment: "[C]arbamazepine can paradoxicallyinduce seizure by worsening hyponatremia".Maiorana E, et al. Carbamazepine-Induced Seizures. 2010 Annual ScientificMeeting of the American Geriatrics Society : abstr. A3, 12 May 2010. Availablefrom: URL: http://www.americangeriatrics.org/annual%5fmeeting/ [abstract] -Italy 803019499

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Reactions 12 Jun 2010 No. 13050114-9954/10/1305-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved