Antiepileptic drugs delay the onset of seizures induced by aminophylline in conscious rats.

Aminophylline, 285.7 +/- 2.19 mg/kg infused intravenously in unanaesthetized rats produced onset of seizures within 3.2 +/- 0.99 minutes. Seizures were repetitive and death occurred in 10.5 +/- 1.75 minutes. Pretreatment of rats with carbamazepine, sodium valproate and diazepam at doses that prevented electroshock induced seizures were effective in significantly postponing seizures and death, but did not reduce mortality. Concomitant EEG studies in aminophylline infused rats showed that cortical excitability evidenced by initial cortical spiking occurred at 42 secs and polyspiking at 165 seconds. Following diazepam, the initial cortical spike was delayed 50 fold, appearing after 36 minutes. Antiepileptic drugs and EEG monitoring may prove useful in patients with status asthmaticus receiving intravenous aminophylline.