[Monitoring long-term therapy with theophylline preparations in children with asthma]

In 78 children (4 to 17 years of age) with moderate or severe asthma who were additionally treated with sustained-release theophylline preparations, different ways of drug monitoring were examined. Analysis of plasma and saliva theophylline was performed by means of high performance liquid chromatography. Saliva theophylline turned out to permit a reliable prediction of plasma theophylline, if an individual regression is calculated for each patient, basing on 3 simultaneously performed measurements of theophylline levels in saliva and plasma within the therapeutic range of 8 to 20 mg/l. In 25 patients theophylline levels were determined in venous and capillary blood. There was an excellent agreement (r = 0.97). Thus, a convenient monitoring of theophylline treatment in children is possible.