Effect of theophylline on diazepam and sodium valproate protection in pentylenetetrazole - kindled seizures in rats.

Theophylline is well known for its convulsant and proconvulsant action. Some experimental studies also suggest that theophylline and other methylxanthines may impair the protection of antiepileptic drugs. The interaction of theophylline and the antiepileptic drugs diazepam and sodium valproate was studied in pentylenetetrazole (PTZ) - kindled seizures in rats. Pretreatment with both diazepam 4 mg/kg and sodium valproate 300 mg/kg, i.p., showed protection against PTZ kindled seizures. Theophylline, 50 mg/kg, i.p., when given before the antiepileptic drugs, failed to reverse their protection. Since theophylline has an adenosine receptor antagonist activity which may be responsible for its convulsant potential, the results indicate non-involvement of adenosinergic mechanisms in the mechanisms of actions of these antiepileptic drugs.