Individualization of theophylline dosage using a single serum sample following a test dose

• Published in: Pediatrics (Evanston) 1982-01, Vol.69 (1), p.70-73
• Main Authors: Shapiro, G G, Koup, J R, Furukawa, C T, Pierson, W E, Gibaldi, M, Fuquay, D, Bierman, C W
• Format: Article
• Language: English
• Subjects: Asthma - drug therapy; Child; Child, Preschool; Humans; Individuality; Theophylline - administration & dosage; Theophylline - blood; Time Factors
• ISSN: 0031-4005; 1098-4275
• DOI: 10.1542/peds.69.1.70

Because formulas for theophylline requirement based on weight alone carry the risk of overdosing and toxicity, this study was designed to test a clearance nomogram for determining daily theophylline requirement after a known initial dose of theophylline. Twenty asthmatic children who had not taken theophylline for at least 36 hours fasted and were given one dose of anhydrous theophylline (5 mg/kg). Six hours later the serum level was measured and the appropriate dosage of sustained-release theophylline to achieve a serum level of 10 micrograms/ml was selected from the clearance nomogram. Three to seven days later a six-hour theophylline level was obtained. Of 20 patients, therapeutic levels of 10 to 30 micrograms/ml were achieved in 15, and the remaining five patients had levels close to this (range 6.2 to 16.0 micrograms/ml). The dosage requirement per 24 hours ranged from 10 to 32 mg/kg/24 hr. This method of determining theophylline requirements for children required measurement of the serum theophylline level only once for the determination of a safe and effective daily dose. It is especially valuable when follow-up is difficult and is a safe way to avoid serious overdosing while being certain of effective dosing.