Differential pharmacokinetics of theophylline in elderly patients.
The clinical use of theophylline as a first-line bronchodilator has declined during the last two decades. However, in many clinical settings, such as an emergency bronchial asthma attack, theophylline may have a first-line role, in combination with beta(2)-adrenoreceptor agonists and corticosteroids, for improving the asthmatic status. Furthermore, many therapeutic mechanisms of theophylline for bronchial asthma have been reported, and recent studies have suggested that theophylline therapy may have a beneficial role in the management of chronic stable asthma as well as exacerbated disease. However, theophylline has a low therapeutic index because the bronchodilation it produces has a linear relationship with logarithmic increases in serum concentration for the therapeutic range of 5-20 mg/L. Thus, the knowledge of its basic pharmacokinetics and the factors that can alter its clearance is clinically relevant for physicians. Especially when used in elderly asthmatic patients, dosage adjustment of theophylline is a requisite since the elderly have several risk factors that may increase the plasma theophylline level, such as reduced clearance, various underlying diseases and multiple coadministered drugs. After theophylline treatment has been initiated, therapeutic drug monitoring is required.
Ohnishi
Akihiro
A
Department of Laboratory Medicine and Internal Medicine, Daisan Hospital, Jikei University School of Medicine, Komae City, Tokyo, Japan. aki-0275@jikei.ac.jp
Kato
Motokazu
M
Kojima
Jun
J
Ushiama
Hideki
H
Yoneko
Maki
M
Kawai
Hiroyuki
H
D000368:Aged; D000375:Aging / Q000378:metabolism; D001993:Bronchodilator Agents / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004347:Drug Interactions; D016903:Drug Monitoring; D006801:Humans; D008099:Liver / Q000378:metabolism; D011110:Polymorphism, Genetic; D013806:Theophylline / Q000009:adverse effects / Q000493:pharmacokinetics* / Q000627:therapeutic use
D001993:Bronchodilator Agents; D013806:Theophylline; D019388:Cytochrome P-450 CYP1A2