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Generic Name: guaifenesin/theophylline (gwye-FEN-e-sin/thee-OFF-i-lin)
Brand Name: Generic only. No brands available.
Guaifenesin/ theophylline is used for:
Preventing and treating symptoms and blockage of airway due to asthma or other lung diseases such as emphysema or bronchitis. It may also be used for other conditions as determined by your doctor.
Guaifenesin/theophylline is a combination xanthine derivative and expectorant. The xanthine derivative works by relaxing the smooth muscle surrounding the bronchial tubes (air passages) of the lungs, allowing the tubes to widen, and making breathing easier. Guaifenesin/theophylline improves contraction of the diaphragm (the major breathing muscle). The expectorant works by increasing respiratory secretions and loosening mucus in the airways.
Do NOT use guaifenesin/ theophylline if:
- you are allergic to any ingredient in guaifenesin/theophylline (including ethylenediamine), 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 have ulcers or a seizure disorder for which you are not taking medicine
- you are taking dipyridamole intravenously (IV), halothane, or St. John's wort
Contact your doctor or health care provider right away if any of these apply to you.
Before using guaifenesin/ theophylline:
Some medical conditions may interact with guaifenesin/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 heart problems (eg, congestive heart failure, cor pulmonale), an irregular heartbeat, a history of ulcers, fluid in the lungs (pulmonary edema), liver problems, fever, viral infection, severe infection (eg, blood infection), thyroid problems, cystic fibrosis, increased acid levels in the body, brain or nerve problems, or seizures (eg, epilepsy)
- if you are in shock
- 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 guaifenesin/theophylline. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Aminoglutethimide, barbiturates (eg, phenobarbital), beta-blockers (eg, propranolol), carbamazepine, hydantoins (eg, phenytoin), isoproterenol, moricizine, propafenone, rifampin, St. John's wort, or sulfinpyrazone because they may decrease guaifenesin/theophylline's effectiveness
- Allopurinol, cimetidine, disulfiram, enoxacin, estrogen, fluvoxamine, interferon alpha-a, macrolide antibiotics (eg, clarithromycin, erythromycin), methotrexate, mexiletine, oral contraceptives (birth control pills), pentoxifylline, quinolone antibiotics (eg, ciprofloxacin), tacrine, thiabendazole, ticlopidine, troleandomycin, verapamil, viloxazine, or zileuton because they may increase the risk of guaifenesin/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, lorazepam), dipyridamole IV, lithium, midazolam, or nondepolarizing muscle relaxants (eg, pancuronium) because their effectiveness may be decreased by guaifenesin/theophylline
This may not be a complete list of all interactions that may occur. Ask your health care provider if guaifenesin/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.
How to use guaifenesin/ theophylline:
Use guaifenesin/theophylline as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Some foods may change the effectiveness or increase the side effects of guaifenesin/theophylline. Talk to your doctor about how you should take guaifenesin/theophylline with regard to food. Do not suddenly change your diet or eating habits without first checking with your doctor.
- Take guaifenesin/theophylline at evenly spaced times throughout the day. Taking guaifenesin/theophylline at the same time each day will help you remember to take it. Contact your doctor with any questions or concerns about the best way to take guaifenesin/theophylline.
- If you miss a dose of guaifenesin/theophylline, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use guaifenesin/theophylline.
Important safety information:
- Use of alcohol may increase the risk of side effects of guaifenesin/theophylline. Talk to your doctor before drinking alcohol while you are taking guaifenesin/theophylline.
- Tell your doctor or dentist that you take guaifenesin/theophylline before you receive any medical or dental care, emergency care, or surgery.
- Carry an ID card at all times that says you take guaifenesin/theophylline.
- Avoid large amounts of food or drink that have caffeine (eg, coffee, tea, cocoa, cola, chocolate).
- Notify your doctor if you develop a new illness, especially if it is accompanied by fever; if a chronic illness becomes worse; if you start or stop smoking cigarettes or marijuana; or if another doctor prescribes a new medication or tells you to stop using a medication that you have already been taking.
- Guaifenesin/theophylline will not stop an asthma attack once one has started. Be sure to always carry appropriate rescue medicine (eg, bronchodilator inhaler) with you in case of an asthma attack.
- If you have more than one doctor, be sure to tell each of your doctors that you are taking guaifenesin/theophylline.
- Diabetes patients - Guaifenesin/theophylline may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
- Lab tests, including blood theophylline levels, may be performed while you use guaifenesin/theophylline. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
- Use guaifenesin/theophylline with caution in the ELDERLY; they may be more sensitive to its effects.
- Caution is advised when using guaifenesin/theophylline in CHILDREN; they may be more sensitive to its effects
- Guaifenesin/theophylline should be used with extreme caution in CHILDREN younger than 6 years old; safety and effectiveness in these children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using guaifenesin/theophylline while you are pregnant. Guaifenesin/theophylline is found in breast milk. If you are or will be breast-feeding while you use guaifenesin/theophylline, check with your doctor. Discuss any possible risks to your baby.
Possible side effects of guaifenesin/ theophylline:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Mild and temporary changes in behavior; temporary increased urination.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; diarrhea; dizziness; fast breathing; heart rhythm problems or irregular heartbeats; nausea; persistent headache; seizures; sleeplessness; tremors; vomiting.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include agitation; chest pain; confusion; decreased urination; fast or irregular heartbeat; headache; increased thirst; irritability; loss of appetite; muscle pain or tenderness; nausea; nervousness; persistent increased urination; restlessness; seizures; severe or persistent diarrhea; stomach pain; tremors or twitching; vomiting, especially of blood.Proper storage of guaifenesin/theophylline:
Store guaifenesin/theophylline at room temperature, between 59 and 86 degrees F (15 and 30 degrees C), in tightly closed container. Store away from heat, moisture, and light. Do not store in the bathroom. Do not refrigerate. Keep guaifenesin/theophylline out of the reach of children and away from pets.
- If you have any questions about guaifenesin/theophylline, please talk with your doctor, pharmacist, or other health care provider.
- Guaifenesin/theophylline is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information is a summary only. It does not contain all information about guaifenesin/theophylline. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.