Anticonvulsant action of diazepam in mice pretreated with caffeine

Anticonvulsant activities of diazepam in mice given pentylenetetrazol (PTZ), as well as effects of diazepam against potentiating activities of caffeine on these convulsions, were studied. Electroencephalographic (EEG) and electromyographic (EMG) recordings and behavioral observations were employed. First spike, clonic and tonic convulsions induced by PTZ were readily recognized from the EEG recording coupled with EMG recording. Pretreatment of mice with diazepam suppressed the incidence of clonic and tonic convulsions, but did not affect the development of first spike. These anticonvulsive effects of diazepam were also observed when PTZ-induced convulsions were potentiated with caffeine, except for clonic convulsion which was not suppressed with diazepam. The mechanisms of the antagonistic effects between diazepam and caffeine are discussed.