Objective: 

Acetaminophen is a widely used analgesic and antipyretic agent. AM404 (N-arachidonoyl-phenolamine) the active metabolite of acetaminophen was reported to reduce epileptic activity by activating the endocannabinoid system in some models of experimental epilepsy. Diazepam is a benzodiazepine with well known anticonvulsant effects. The objective of the present study was to investigate the effects of acetaminophen and diazepam comparatively on penicillin induced epilepsy in rats.

Methods: 

Rats were anesthetized with urethane (1.25 g/kg, intraperitoneal) and placed in stereotaxic frame. Body temperature was maintained at 37°C by a heating blanket. The left cerebral cortex was exposed by craniotomy. The epileptic focus was produced by 500 units penicillin G injection into the somatomotor cortex. Acetaminophen (100 mg/kg, intravenous), diazepam (5 mg/kg, intravenous) and diazepam + acetaminophen were administrated 30 minutes after penicillin injection and their effects were examined comperatively on epileptiform activity. The electrocortigography (ECoG) activity was monitored for 2 hours.

Results: 

Intracortical injection of penicillin (500 units) induced epileptiform activity in all groups. Statistical analysis was estimated by one-way ANOVA and Post Hoc LSD tests. Diazepam (5mg kg, intravenous) significantly decreased the epileptiform activity in the 10th minute after penicillin injection. The administration of acetaminophen (100 mg/kg, intravenous) did not influence the penicillin induced epileptiform activity. Also no significant diffirence was found between antiepileptic effects of diazepam and diazepam + acetaminophen groups.

Conclusions: 

The results of present study indicate that acetaminophen did not influence the penicillin-induced epileptiform activity and there are no interactions between acetaminophen and diazepam on penicillin-induced epilepsy. Further investigations are needed concerning the fundimental mechanisms of acetaminophen on epilepsy.