This medication contains 2 drugs (oxtriphylline and guaifenesin) and is used to treat and prevent wheezing and trouble breathing caused by ongoing lung disease (such as asthma, chronic bronchitis, emphysema). Oxtriphylline belongs to a class of drugs known as xanthines and is changed in the body to theophylline. Theophylline works by relaxing the muscles around the airways so that they open up and you can breathe more easily. It also decreases the lungs' response to irritants. Guaifenesin is an expectorant that helps thin and loosen mucus in the lungs, making it easier to cough up the mucus. Controlling symptoms of breathing problems can decrease time lost from work or school.

This medication does not work right away and should not be used to relieve sudden attacks of breathing trouble. If an attack occurs, use your quick-relief inhaler (such as albuterol) as prescribed by your doctor.

Take this medication by mouth as directed by your doctor, usually every 6 hours with a full glass of water (8 ounces or 240 milliliters). If stomach upset occurs, take it with food. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

The dosage is based on your age, medical condition, response to treatment, and other drugs you may be taking. (See also Drug Interactions section.)

Alcohol and caffeine can increase the side effects of this medication. Avoid drinking large amounts of beverages containing alcohol or caffeine (coffee, tea, colas), eating large amounts of chocolate, or taking nonprescription products that contain caffeine.

This medicine works best when the amount in your body is kept at a constant level. Use this drug at evenly spaced intervals. To help you remember, take it at the same times each day. Do not increase your dose unless your doctor directs you to do so. Taking too much of this medication may cause serious side effects.

Learn which of your medications you should use every day (controller drugs such as this medication) and which you should use if your breathing suddenly worsens (quick-relief drugs). Ask your doctor ahead of time what you should do if you have new or worsening cough or shortness of breath, wheezing, increased sputum, worsening peak flow meter readings, waking up at night with trouble breathing, if you use your quick-relief inhaler more often (more than 2 days a week), or if your quick-relief inhaler does not seem to be working well. Learn when you can treat sudden breathing problems by yourself and when you must get medical help right away.

Stomach pain/cramping, pounding heartbeat, nausea, vomiting, headache, trouble sleeping, diarrhea, irritability, restlessness, shaking, and increased urination may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• fast/irregular heartbeat
• seizures

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as dyphylline, theophylline); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• heart problems (such as angina, fast/irregular heartbeat, heart failure, recent heart attack)
• high blood pressure
• kidney disease
• liver disease
• seizures
• stomach/intestinal ulcer
• thyroid problems (underactive or overactive)
• a certain lung problem (cystic fibrosis)
• fluid in the lungs

If you get sick or have a fever while taking this medication, tell your doctor right away. The dose of your medicine may need to be adjusted.

This product contains sugar and alcohol. If you have diabetes, alcohol dependence, or liver disease, consult your doctor or pharmacist about using this product safely.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. However, it is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

A product that may interact with this drug is:

• lithium

Other medications can affect the removal of this medication from your body, which may affect how this medication works. Examples include cimetidine, ciprofloxacin, disulfiram, fluvoxamine, interferon alpha, certain macrolide antibiotics (clarithromycin, erythromycin), mexiletine, nefazodone, St. John's wort, drugs to treat seizures (such as carbamazepine, phenobarbital, phenytoin), tacrine, among others.

Check the labels on all your medicines (such as cough-and-cold products, diet aids) because they may contain ingredients (such as ephedrine, pseudoephedrine, phenylephrine) that could increase the side effects of this medication. Ask your pharmacist about using those products safely.

Oxtriphylline is very similar to theophylline. Do not take medications containing theophylline while using oxtriphylline.

Cigarette smoking decreases blood levels of this medication. Tell your doctor if you smoke or if you have recently stopped smoking.

This medication may interfere with certain lab tests (such as stress tests, uric acid levels), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: agitation, severe vomiting, extreme thirst, ringing in the ears, increased sweating, fainting, chest pain, fast/irregular heartbeat, seizures.

Do not share this medication with others.

Avoid substances that can worsen breathing problems by causing irritation or allergic reaction, such as smoke, pollen, pet dander, dust, and mold.

Lab and/or medical tests (such as blood levels for this drug) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

To help loosen mucus, drink plenty of fluids while taking this medication unless your doctor instructs you otherwise.

If you have asthma, learn to use a peak flow meter, use it daily, and promptly report worsening breathing problems (such as readings in the yellow/red range, increased use of quick-relief inhalers).

Because the flu virus can worsen breathing problems, ask your doctor or pharmacist if you should have a flu shot every year.

If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).