Effect of aminophylline on the protective action of common antiepileptic drugs against electroconvulsions in mice.

The increasing amount of data tends to suggest that adenosine-mediated inhibition may play a role in the anticonvulsant activity of a number of antiepileptic drugs. Consequently, we tried to reverse the protective action of acetazolamide [(40 and 80 mg/kg) i.p.; 60 min before the test]; carbamazepine (20 and 30 mg/kg i.p., 60 min); diazepam (5 and 10 mg/kg i.p., 60 min); diphenylhydantoin (8 and 12 mg/kg i.p., 120 min), phenobarbital (20 and 30 mg/kg i.p., 120 min) and valproate (200 and 300 mg/kg i.p., 30 min) with aminophylline (50 and 100 mg/kg i.p., 30 min) against electroconvulsions in mice. Aminophylline markedly decreased the anticonvulsant efficacy of almost all drugs studied, acetazolamide (40 and 80 mg/kg) and carbamazepine (30 mg/kg) being the only exceptions. The ethylenediamine component of aminophylline did not modify the anticonvulsant activity at all. These results seem to support the suggestion that aminophylline-induced blockade of adenosine receptors might be involved in the reversal of the protective action of at least some drugs studied. Regardless of the nature of the aminophylline-induced impairment in the anticonvulsant efficacy of a number of antiepileptic drugs, the use of methylxanthines in epileptic patients for the treatment of obstructive lung diseases should be avoided.