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Apparent decrease in population clearance of theophylline: Implications for dosage *
Author(s) -
Asmus Michael J.,
Weinberger Miles M.,
Milavetz Gary,
Marshik Patricia,
Teresi Mary E.,
Hendeles Leslie
Publication year - 1997
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/s0009-9236(97)90043-6
Subject(s) - theophylline , medicine , dosing , asthma , bronchodilator , population , serum concentration , pharmacokinetics , dosage form , anesthesia , pharmacology , environmental health
Background Having observed in recent years that the theophylline dose requirements needed to attain peak serum concentrations of 10 to 20 μg/ml infrequently reached previously described mean values, we hypothesized that a downward shift in the range of dose requirements had occurred among patients with asthma. Study design We examined dosage requirements needed to attain peak serum concentrations of 10 to 20 μg/ml in all patients with chronic asthma treated with theophylline by the Pediatric Allergy and Pulmonary Clinic at the University of Iowa from 1990 to 1994 ( n = 300) and at the Pediatric Pulmonary Clinic at the University of Florida from 1992 to 1995 ( n = 93). We then compared these doses to previous dose requirements from 1978 to 1983 determined in the same manner. Results Despite similar mean peak serum concentrations during both time periods (14 μg/ml), mean theophylline dosage requirements during the period of this study were approximately 25% lower among all age groups than those previously observed ( p < 0.001). There were no significant differences in mean dosage requirements between the Iowa and Florida patients in any age group examined. Conclusions Theophylline dose requirements needed to attain serum concentrations of 10 to 20 μg/ml have decreased significantly from those on which current dosing recommendations are based. This suggests a decrease in mean clearance of the population. Clinical Pharmacology & Therapeutics (1997) 62 , 483–489; doi: