title: The effect of smoking on theophylline kinetics in healthy and asthmatic elderly males.
abstract: The effect of smoking on theophylline kinetics was investigated in four groups of males over the age of 65 yr. The first group consisted of 14 healthy non-smoking males, the second group consisted of 8 healthy smoking males. The first and the second groups were administered a single oral dose of 300 mg tablet of sustained-release anhydrous theophylline product and serial blood samples were collected over 24 hr. The third group consisted of 22 clinically stable asthmatic non-smoking males, the fourth group consisted of 9 clinically stable asthmatic smoking males. The third and the fourth groups, were administered multiple oral doses equivalent to 300 mg of anhydrous theophylline from sustained-release Oxtriphylline every 12 hr for 72 hr; and blood samples were collected every two hours between 72-82 hrs. Serum theophylline concentrations were determined by HPLC. There were no significant differences between the smokers and non-smokers in observed maximum concentration (Cmax), its time (tmax), the area under the time-concentration curve (AUCo-t), and total body clearance rate (Cl). Aging appears to offset the known smoking inducing effect on the hepatic microsomal enzymes.
authors.affiliation: College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee 32307.
authors.forename: S
authors.initials: S
authors.lastname: Samaan
authors.forename: R
authors.initials: R
authors.lastname: Fox
mesh_terms: D000368:Aged; D001249:Asthma / Q000378:metabolism*; D004347:Drug Interactions; D006801:Humans; D008297:Male; D012907:Smoking / Q000378:metabolism*; D013806:Theophylline / Q000493:pharmacokinetics*
chemical_list: D013806:Theophylline