Ketamine and e.e.g. seizure waves: interaction with anti-epileptic drugs

When unrestrained cats were with ketamine 2-6 mg kg-1 i.v., anaesthesia was associated with seizure waves induced in the cortical e.e.g. After cats were pretreated with trimethadione 500 mg kg-1 i.p., ketamine did not induce seizure waves. Pretreatment with diphenylhydantoin 25 or 100 mg kg-1 i.p. slightly enhanced seizure waves following ketamine. In both situations the anaesthetic effect of ketamine remained unaffected.