1. The effects of the non-opioid antitussives caramiphen and carbetapentane and of the anticonvulsants 5,5-diphenylhydantoin and MK 801 were tested towards hypoxia-induced electrical changes in rat hippocampal slices. 2. The incidence of appearance of hypoxia-induced epileptiform bursting was significantly decreased (P < 0.05) by carbetapentane (50-100 microM), caramiphen (50-100 microM), 5,5-diphenylhydantoin (25-50 microM), and the glutamate antagonist dizocilpine (MK 801, 25-50 microM). 3. The incidence of reappearance of the CA1 population spike after hypoxia was significantly increased (P < 0.05) by carbentapentane (50-100 microM), caramiphen (50-100 microM), 5,5-diphenylhydantoin (25-50 microM), and MK 801 (25-50 microM). 4. The results suggest a useful role for non-opioid antitussives and some anticonvulsants in the treatment of hypoxia-induced functional disturbances.