[Methylxanthines and benzodiazepine antagonism].

The mode of action of methylxanthines and benzodiazepines are not yet fully elucidated. Interaction with antagonizing effect occurs between these two preparations, probably with influence upon some of the same cellular systems. At least two types of benzodiazepine receptors in the cerebrum have been described. These are presumed to be placed in the neighbourhood of gamma-aminobutyric-acid (GABA) receptors and they probably modify the functions of these. In addition, influence on other transmitter systems in the CNS occurs with release of adenosine and reduction of the acetyl choline content. It has been demonstrated that methylxanthines are adenosine-blocking but they also release catecholamines from the suprarenal cortex and sympathetic nerve-ends both centrally and peripherally. In clinical practice, the antagonistic effect of employing methylxanthines in patients sedated with benzodiazepines has been demonstrated. Administration of 1-2 mg/kg of aminophyllin usually results in immediate effect and these patients woke up immediately after injection. When benzodiazepines and methylxanthines are administered simultaneously the total result will be difficult to predict.