Theophylline is a bronchodilator that is used to treat symptoms of asthma, bronchitis, emphysema, and other breathing problems.

Theophylline may also be used for purposes not listed in this medication guide.

Never use theophylline in larger amounts, or for longer than prescribed. Seek medical attention if your breathing problems get worse quickly, or if you think your medications are not working as well.

Overdose can occur if you take too much theophylline at one time, or if your daily doses are too high.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact with theophylline.

Theophylline comes as an extended-release (long-acting) tablet, extended-release capsule, and a solution (liquid) to take by mouth. It usually is taken every 6, 8, 12, or 24 hours. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take theophylline exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Take this medication with a full glass of water on an empty stomach, at least 1 hour before or 2 hours after a meal. Extended-release capsules (e.g., Theo-Dur Sprinkles) may be swallowed whole or opened and the contents mixed with soft food and swallowed without chewing.

Swallow the extended-release tablets whole; do not chew or crush them.

Theophylline controls symptoms of asthma and other lung diseases but does not cure them. Continue to take theophylline even if you feel well. Do not stop taking theophylline without talking to your doctor.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Never use theophylline in larger amounts, or for longer than prescribed.

Theophylline is not a rescue medicine for asthma or bronchospasm attacks. Use only fast-acting inhalation medicine for an attack. Seek medical attention if your breathing problems get worse quickly, or if you think your medications are not working as well.

Swallow the capsule or tablet whole and do not crush or chew it. You may break a scored tablet in half if needed to get the correct dose.

Some tablets are made with a shell that is not absorbed or melted in the body. Part of this shell may appear in your stool. This is normal and will not make the medicine less effective.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Your dose and the number of times you take theophylline daily will depend on the reason you are taking this medication.

Follow your doctor's instructions about whether to take your medication with food or on an empty stomach.

Your dose needs may change if you are ill, or if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using only the form and strength your doctor prescribes.

You will need regular medical tests to be sure you are using the right dose. Do not change your dose or dosing schedule without your doctor's advice.

Theophylline doses are based on weight in children. Your child's dose needs may change if the child gains or loses weight.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using theophylline.

Store at room temperature away from moisture, heat, and light.

You should not use theophylline if you are allergic to it.

Tell your doctor if you have ever had:

• a gastric or peptic ulcer;

• a serious infection called sepsis;

• liver disease (especially cirrhosis or hepatitis);

• fluid in your lungs;

• heart problems;

• a thyroid disorder;

• seizures; or

• kidney disease.

Tell your doctor if you drink alcohol, or if you smoke or have recently quit smoking cigarettes or marijuana.

Also tell your doctor if you have been sick with a high fever (102 degrees or higher) for 24 hours or longer.

Tell your doctor if you are pregnant or breastfeeding.

Do not give theophylline to a child without medical advice.

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. Seizures caused by a theophylline overdose can cause death or permanent brain damage.

Theophylline overdose can occur if you accidentally take too much at one time. Overdose can also occur slowly over time if your daily doses are too high. To be sure you are using the correct dose, your blood will need to be tested often.

Overdose symptoms may include severe nausea and vomiting, seizure, slow heart rate, weak pulse, or fainting.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Drinking or eating foods high in caffeine, like coffee, tea, cocoa, and chocolate, may increase the side effects caused by theophylline. Avoid large amounts of these substances while you are taking theophylline.

Do not start or stop smoking without first talking to your doctor. Smoking changes the way your body uses theophylline, and you may need to use a different dose.

Avoid taking an herbal supplement containing St. John's wort.

Avoid driving or hazardous activity until you know how theophylline will affect you. Your reactions could be impaired.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Theophylline may cause serious side effects. Call your doctor at once if you have:

• severe or continued vomiting;

• ongoing headache, trouble sleeping;

• rapid heartbeats;

• a seizure;

• new signs of illness (especially fever);

• low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling; or

• high blood sugar--increased thirst, increased urination, dry mouth, fruity breath odor.

Serious side effects may be more likely in older adults.

Common side effects of theophylline may include:

• nausea, vomiting, diarrhea;

• headache;

• sleep problems (insomnia);

• tremors;

• sweating; or

• feeling restless or irritable.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

If you take St. John's wort regularly, do not stop taking it without first asking your doctor. Starting or stopping St. John's wort can affect your blood levels of theophylline.

Many drugs can affect theophylline. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to theophylline.

Do not change from one brand of theophylline to another without talking to your doctor.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.