Do not take guaifenesin and theophylline without first talking to your doctor if you have
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a stomach ulcer; or
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epilepsy or another seizure disorder.
It may be dangerous to take guaifenesin and theophylline if you have either of these conditions.
Before taking this medication, tell your doctor if you have
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high blood pressure, irregular heartbeats, congestive heart failure, or any other type of heart disease;
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fluid in your lungs;
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a thyroid condition;
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a fever;
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liver disease; or
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kidney disease.
You may not be able to take guaifenesin and theophylline, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.
Guaifenesin and theophylline is in the FDA pregnancy category C. This means that it is not known whether guaifenesin and theophylline will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant.
Guaifenesin and theophylline passes into breast milk and may affect a nursing infant. Do not take guaifenesin and theophylline without first talking to your doctor if you are breast-feeding a baby.
If you are over 60 years of age, you may be more likely to experience side effects from guaifenesin and theophylline. You may require a lower dose of this medication.
Take guaifenesin and theophylline exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.
Take each dose with a full glass of water. Increase your fluid intake during the day to help relieve congestion and thin mucus.
Guaifenesin and theophylline can be taken with food to lessen stomach upset.
Take your doses at the same time every day to keep a constant level of guaifenesin and theophylline in your blood.
Do not crush or chew any extended-release formulation of guaifenesin and theophylline. Swallow the medication whole. It is specially formulated to release slowly in your body. If you do not know whether you have an extended-release formulation, ask your pharmacist.
Shake the liquid forms of this medication well before use. To ensure that you get a correct dose, measure the liquid with a dose-measuring cup or spoon, not a regular tablespoon. If a spoon or cup is not provided with the medication and you do not have one, ask your pharmacist where you can get one.
Do not switch brand or formulation (tablet, capsule, liquid) without the approval of your doctor. A change in brand or formulation may necessitate a different dosage.
Store guaifenesin and theophylline at room temperature away from moisture and heat.
Take the missed dose as soon as you remember. However, if it is almost time for your next
regularly scheduled dose, skip the missed dose and take the next one as directed.
If you experience any of the following serious side effects, stop taking guaifenesin and theophylline and seek emergency medical attention:
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an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
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seizures;
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increased or irregular heartbeats; or
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severe nausea or vomiting.
Other, less serious side effects may occur, although they are not common at appropriate doses. Continue to take guaifenesin and theophylline and talk to your doctor if you experience
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slight nausea, decreased appetite, or weight loss;
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restlessness, tremor, or insomnia; or
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headache, lightheadedness, or dizziness.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
Do not crush or chew any extended-release formulation of guaifenesin and theophylline. Swallow the medication whole. It is specially formulated to release slowly in your body. If you do not know whether you have an extended-release formulation, ask your pharmacist.
Call your doctor right away if you experience nausea, vomiting, insomnia, restlessness, seizures, an increased heart rate, or a headache. These symptoms could be signs of too much theophylline in your blood.
Do not start or stop smoking without first talking to your doctor. Smoking changes the way your body uses theophylline, and you may need a dosage adjustment.
Do not take more of this medicine than is prescribed without consulting your doctor. Seek medical attention if you are having increasingly difficult breathing.
Use caution when driving, operating machinery, or performing other hazardous activities. Guaifenesin and theophylline may cause dizziness. If you experience dizziness, avoid these activities.
Avoid alcohol or use it with moderation while taking guaifenesin and theophylline. Alcohol can increase the effects of theophylline leading to side effects.
Do not start or stop smoking without first talking to your doctor. Smoking changes the way your body uses theophylline, and you may need a dose adjustment.
Do not switch brand or formulation (tablet, capsule, liquid) without the approval of your doctor. A change in brand or formulation may necessitate a different dosage.
Avoid eating excessive amounts of grilled or char-broiled foods. These foods may affect how much theophylline you need. Talk to your doctor before making changes in your diet.
Avoid excessive use of caffeinated beverages such as coffee, tea, and cola. Theophylline is related chemically to caffeine. You may experience some side effects if you consume too much caffeine.
Guaifenesin and theophylline interacts with many other drugs. Tell your doctor and pharmacist about all other medications that you are taking, including herbal remedies, vitamins, and other nonprescription items, and do not start or stop taking any medication without first talking to your doctor.
Before taking guaifenesin and theophylline, tell your doctor if you are taking any of the following medicines:
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a macrolide antibiotic such as clarithromycin (Biaxin), erythromycin (Ery-Tab, E.E.S, E-Mycin, others), troleandomycin (TAO), and others;
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a fluoroquinolone antibiotic such as ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Noroxin), grepafloxacin (Raxar), and others;
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birth control pills such as Ortho-Novum, Ovral, Lo-Ovral, Desogen, Levlen, Tri-Levlen, Triphasil, Alesse, and others;
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a thyroid hormone such as levothyroxine (Synthroid, Levoxyl, Levothroid, others), and others;
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an interferon product such as Intron A, Alferon N, Infergen, Roferon-A, Betaseron, Avonex, Actimmune, and others;
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a calcium channel blocker such as diltiazem (Cardizem, Dilacor XR, Tiazac), nifedipine (Procardia, Adalat), verapamil (Verelan, Calan, Isoptin), and others;
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a beta-blocker such as propranolol (Inderal), carteolol (Cartrol), nadolol (Corgard), pindolol (Visken), labetalol (Normodyne, Trandate), timolol (Blocadren), and others;
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a beta-agonist such as albuterol (Ventolin, Proventil, Volmax, others), bitolterol (Tornalate), pirbuterol (Maxair), salmeterol (Serevent), and others;
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a diuretic (water pill) such as furosemide (Lasix), bumetanide (Bumex), ethacrynic acid (Edecrin), or torsemide (Demadex);
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a barbiturate such as phenobarbital (Luminal, Solfoton), and others;
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cimetidine (Tagamet, Tagamet HB);
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isoniazid (Nydrazid);
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ketoconazole (Nizoral);
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sulfinpyrazone (Anturane);
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allopurinol (Zyloprim);
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lansoprazole (Prevacid);
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thiabendazole (Mintezol);
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disulfiram (Antabuse);
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influenza vaccine;
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fluvoxamine (Luvox);
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methotrexate (Rheumatrex);
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mexiletine (Mexitil);
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propafenone (Rythmol);
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tacrine (Cognex);
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ticlopidine (Ticlid);
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aminoglutethimide (Cytadren);
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carbamazepine (Tegretol);
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moricizine (Ethmozine);
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phenytoin (Dilantin);
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rifampin (Rifadin); or
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sucralfate (Carafate).
You may require a dosage adjustment or special monitoring during your treatment if you are taking any of the medications listed above.
Drugs other than those listed here may also interact with guaifenesin and theophylline or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.
Seek emergency medical attention.
Symptoms of a guaifenesin and theophylline overdose include nausea, vomiting, headache, insomnia, tremor (shaking hands or twitching), irritability, restlessness, seizures, and fast or irregular heartbeats.
