The study of almagel effect on euphylline absorption in children with bronchial asthma showed a decrease of theophylline concentration by 10-15% ten days after the combined administration of the drugs. The absence of the change in the blood theophylline concentration three days after administration of almagel against the background of euphylline indicates that the reason for a decrease of euphylline absorption is not the absorbing and lubricating properties of almagel but probably almagel-induced reduction of the inflammation of the gastrointestinal tract mucosa (hyperemia, increased vascular permeability) caused by euphylline.