The question of dosage: Clinical Studies of high and low dosage theophylline and in asthmatic children

Summary Studies carried out in asthmatic children being treated with theophylline have shown that although the child with severe asthma may need to obtain serum theophylline levels of 10 to 20 μg/ml, those with less severe symptoms may require only 3 to 8 μg/ml which can normally be achieved with an oral dosage ranging from 3 to 10.7 mg/kg 6-hourly. It has been noted, however, that with the exception of newborn and premature infants, the younger the child the more rapid the clearance rate of theophylline and, although inter-patient variability is less than in adults, a definite and significant intra-patient variability has been recorded in some children after chronic administration, both in those on low-dose and high-dose therapy. Monitoring of theophylline and an awareness of such patient variability, therefore, are important aspects of the treatment of asthmatic children.