Theophylline antagonizes flurazepam-induced depression of cerebral cortical neurons.

Intravenously administered theophylline (50--100 mg/kg) antagonized the depressant actions of adenosine and flurazepam on rat cerebral cortical neurons. When assessed in conjunction with recent reports that theophylline competes with diazepam for binding sites in brain tissue, this finding suggests that one action of the benzodiazepines may be exerted at a purinergic receptor associated with central neurons.