Phenytoin: Plasma levels and behavioral changes associated with suppression of auditory evoked potentials in the cat

Phenytoin (PHT) administration caused near total or total suppression of auditory evoked field potentials and brainstem auditory evoked potentials at mean plasma levels of 28.1–30.5 μg/ml. The suppression lasted for a mean of 53.5 hr and was accompanied by ataxia and other signs of PHT toxicity. Visual evoked field potentials were not consistently affected. This action may be mediated by effects on peripheral auditory receptor mechanisms.