[Pharmacokinetics of theophylline in infantile bronchial asthma. Clinical findings].

Authors have studied pharmacokinetic parameters of theophylline in a sample of 21 children with bronchial asthma, through evolution of plasmatic concentrations, evaluated by RIA, in order to appreciate therapeutic response to it depending on the time-variation of such concentrations. They have determined that theophylline's kinetic obeys to a "depending dose" reaction represented by Michaelis-Menten equation. This induce them to refuse those therapeutic methods based on the establishment of maintaining doses depending on drug clearance, as minimal increases in posology can give spectacular decreases of drug clearance. They have also seen that great amplitude of individual variation for pharmacokinetics parameters of theophylline, in intra-patient studies is very short.