Detailed Drug Information:

DRUG CLASS AND MECHANISM: Theophylline belongs to a class ofmedications called bronchodilators, used in treating asthma and otherairway diseases. Asthma is a breathing problem involving narrowing of theairways. Airways are breathing passages that allow air to move in and outof the lungs. Airways can be narrowed due to accumulation of mucus, spasmof the muscles that surround these airways, or swelling of the lining ofthe airways. Airway narrowing leads to symptoms of shortness of breath, wheezing, cough and congestion. The narrowed airways can open eitherspontaneously or from medications. Medications that open airways arecalled bronchodilators. Theophylline opens airways by relaxing the smoothmuscles in the walls of the airways. Theophylline can also be helpful inpatients with emphysema and chronic bronchitis when their symptoms arepartially related to reversible airway narrowing. Theophylline alsostrengthens right heart function and diaphragm movement.

PREPARATIONS: Tablets (100mg, 200mg 300mg, 400mg, 450mg),syrups, solutions.

STORAGE: Theophylline should be stored at room temperature in atightly closed container.

PRESCRIBED FOR: Theophylline is used in the relief andprevention of airway narrowing (bronchospasm) in patients with asthma.Theophylline can also be used in treating patients with emphysema andchronic bronchitis when their symptoms are related to reversible airwaynarrowing. Theophylline can be administered together with otherbronchodilators, such as albuterol (Ventolin, Proventil) for addedbronchodilator effect.

DOSING: Theophylline may be taken with or without food, butshould not be crushed or chewed. Theophylline is metabolized mainly by theliver and dosages should be reduced in patients with liver dysfunction. Onthe other hand, theophylline is generally metabolized more rapidly insmokers (both tobacco and marijuana) and higher dosages may be required.High blood theophylline levels can lead to symptoms of toxicity (seebelow). Therefore, theophylline blood levels are monitored periodicallyduring treatment to assure achievement of optimal and safe levels.

DRUG INTERACTIONS: Certain groups of patients metabolizetheophylline slowly, and can develop elevated blood levels and potentialtoxicity even on usual doses. These patients include those with liverdisease, older men with chronic lung diseases, infants, patients with highfever or heart failure, and patients taking other medications thatincrease blood theophylline levels. Examples of medications that canelevate theophylline blood levels include ephedrine, allopurinol (Zyloprim), cimetidine (Tagamet), ciprofloxacin (Cipro), erythromycin,oral contraceptives, and propranolol (Inderal). Theophylline toxicity cancause nausea, vomiting, insomnia, seizures, agitation and life-threateningheart rhythm abnormalities. Theophylline should be used cautiously inpatients with high blood pressure, peptic ulcer disease, seizuredisorders, and serious heart disease, especially with heart rhythmproblems.

SIDE EFFECTS: Common side effects include nausea, vomiting,diarrhea, headaches, irritability, flushing and palpitations. More seriousside effects include seizures and ventricular heart arrhythmias.