- Preventing and treating symptoms and blockage of airway due to asthma or other lung diseases (eg, emphysema, bronchitis). It may also be used for other conditions as determined by your doctor.
- Theophylline is a xanthine derivative. It works by relaxing the muscle around the airways in the lungs, which allows them to widen and makes breathing easier. It also improves contraction of the diaphragm (the major breathing muscle) and decreases the response of the airways to irritants.
Do NOT use theophylline if:
- you are allergic to any ingredient in theophylline, similar medicines (eg, aminophylline), or xanthines (eg, caffeine, chocolate)
- you are using large amounts of other products that contain xanthine (such as chocolate or caffeinated drinks)
- you are taking dipyridamole intravenously (IV), febuxostat, halothane, or St. John’s wort
- Contact your doctor or health care provider right away if any of these apply to you.
Before using theophylline:
Some medical conditions may interact with theophylline. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have a history of heart problems (eg, congestive heart failure, cor pulmonale), an irregular heartbeat, liver problems (eg, cirrhosis, hepatitis), viral infection, thyroid problems, increased acid levels in the body, brain or nerve problems, or seizures (eg, epilepsy)
- if you are in shock or have a fever, an ulcer, a severe infection, cystic fibrosis, or fluid in the lungs (pulmonary edema)
- if you smoke, are stopping or starting smoking, or are exposed to the smoke from cigarettes or marijuana
- if you are in the last 3 months of pregnancy
Some MEDICINES MAY INTERACT with theophylline. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Aminoglutethimide, barbiturates (eg, phenobarbital), carbamazepine, hydantoins (eg, phenytoin), isoproterenol, moricizine, rifampin, St. John’s wort, or sulfinpyrazone because they may decrease theophylline’s effectiveness
- Allopurinol, beta-blockers (eg, propranolol), cimetidine, disulfiram, enoxacin, estrogen, febuxostat, fluvoxamine, interferon alpha, macrolide antibiotics (eg, clarithromycin, erythromycin), methotrexate, mexiletine, oral contraceptives (birth control pills), pentoxifylline, propafenone, quinolone antibiotics (eg, ciprofloxacin), tacrine, thiabendazole, ticlopidine, troleandomycin, verapamil, viloxazine, or zileuton because they may increase the risk of theophylline’s side effects
- Ephedrine because the risk of side effects, such as nausea, nervousness, and trouble sleeping, may be increased
- Halothane because the risk of side effects such as irregular heartbeat may be increased
- Ketamine because the risk of seizures may be increased
- Adenosine, benzodiazepines (eg, diazepam, flurazepam, lorazepam, midazolam), dipyridamole IV, lithium, or nondepolarizing muscle relaxants (eg, pancuronium) because their effectiveness may be decreased by theophylline
This may not be a complete list of all interactions that may occur. Ask your health care provider if theophylline may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.