Abstract |
Theophylline kinetic studies, serial spirometric function tests, and arterial blood gas determinations were performed in 39 adult men with stable chronic obstructive airway disease ( COPD). Subjects were given an intravenous aminophylline loading dose of 5.6 mg/kg and a maintenance dose of 0.9 mg/kg/hr for 6 hours. Elderly (greater than 60 years old) nonsmoking subjects had 36% lower theophylline clearance (Cl) and a 40% longer serum theophylline elimination t1/2 than did middle-aged (less than 60 years old) nonsmoking subjects (mean +/- SE; clearances of 32.6 +/- 3.2 [n = 13] and 50.7 +/- 8.5 ml/kg/hr [n = 8] and t1/2s of 11.0 +/- 0.8 and 7.4 +/- 0.8 hours, respectively). There were also differences in Cl and t1/2 between elderly and middle-aged subjects in both the smoking and nonsmoking groups: elderly group, Cl = 43.6 +/- 3.7 mg/kg/hr and t1/2 = 9.0 +/- 0.7 hours; middle-aged group, Cl = 57.6 +/- 6.0 mg/kg/hr and t1/2 = 6.7 +/- 0.6 hours). There was consistent improvement in spirometric functions in both nonsmoking and smoking elderly subjects: percent changes in forced expiratory volume in 1 second of 19% to 25%; in forced vital capacity of 25% to 31%; in forced expiratory flow at 25% to 75% of vital capacity of 59% to 67%; and in maximum mid-flow time of -25% to -30%, at serum theophylline concentrations of 10 to 13 mg/L (group mean). We conclude that elderly nonsmoking subjects with COPD cleared theophylline more slowly than did middle-aged, nonsmoking subjects with COPD.(ABSTRACT TRUNCATED AT 250 WORDS)
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Authors | W Y Au, A K Dutt, N DeSoyza |
Journal | Clinical pharmacology and therapeutics
(Clin Pharmacol Ther)
Vol. 37
Issue 4
Pg. 472-8
(Apr 1985)
ISSN: 0009-9236 [Print] United States |
PMID | 3919989
(Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Carbon Dioxide
- Theophylline
- Oxygen
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Topics |
- Aged
- Aging
- Analysis of Variance
- Carbon Dioxide
(blood)
- Half-Life
- Humans
- Hydrogen-Ion Concentration
- Infusions, Parenteral
- Kinetics
- Lung Diseases, Obstructive
(drug therapy, metabolism)
- Male
- Middle Aged
- Oxygen
(blood)
- Smoking
- Spirometry
- Theophylline
(blood, metabolism, therapeutic use)
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