Which of the following agent increases blood levels of theophylline?
Factors Affecting Clearance of Theophylline: Increased clearance: Enzyme induction (mainly CYP1A2) by co-administered drugs (e.g., rifampicin, barbiturates, ethanol) Smoking (tobacco, marijuana) CYP1A2 induction High-protein, low-carbohydrate diet Barbecued meat Childhood Decreased clearance: CYP inhibition (cimetidine, erythromycin, ciprofloxacin, allopurinol, fluvoxamine, zileuton, zafirlukast) Congestive hea failure Liver disease Pneumonia Viral infection and vaccination High-carbohydrate diet Old age
Erythromycin
Rifampicin
Tobacco
Ethanol