Ribavirin influence on theophylline plasma levels in adult and children.

The pharmacokinetics of ribavirin and aminophylline (theophylline ethylenediamine) after oral administration in healthy adults and in children suffering from viral infections of the respiratory tract, with superimposition of bronchial asthma or asthmatic syndrome, was studied. By the prompt-release formulation of aminophylline the hematic peak is reached within the first 30 min (9.03 micrograms/ml) from intake, whereas by the sustained-release formulation the peak is reached only within the 5th hour (8.5 micrograms/ml). After administration of ribavirin no interferences with the clearance of theophylline both in adults and children were noted.