Ketamine hydrochloride, a dissociative anesthetic, has proconvulsant and anticonvulsant properties. It should be used with caution in epilepsy patients. Of eight epilepsy patients who underwent dental work with ketamine, two had focal motor seizures and another had a generalized tonic-clonic seizure. In some patients with epileptiform activity on their baseline EEGs, particularly those receiving 2–4 mg/kg intravenous doses, the activity progressed to electrical seizure.72 EEG recordings in all of these patients returned to their preanesthetic baseline within a week.73
If a clinical seizure occurs during ketamine use, further administration of ketamine to deepen anesthesia should be avoided. Instead, a CNS depressant, such as a barbiturate or benzodiazepine, should be used.3
In other studies, ketamine did not increase epileptiform or seizure activity in epilepsy subjects.74,75 Owing to the mixed depressant-stimulant effects of ketamine, epilepsy patients should be adequately premedicated with anticonvulsants and sedatives.
Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.
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