Theophylline and guaifenesin (Oral)
Medically reviewed by Drugs.com. Last updated on Feb 26, 2022.
Chemical Class: Methylxanthine
Uses for theophylline and guaifenesin
Theophylline and guaifenesin combination is used to treat or prevent the symptoms of asthma or to treat chronic bronchitis and emphysema. Theophylline and guaifenesin relieves cough, wheezing, shortness of breath, and troubled breathing. It works by opening up the bronchial tubes (air passages) of the lungs and increasing the flow of air through them.
Theophylline and guaifenesin is available only with your doctor's prescription.
Before using theophylline and guaifenesin
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For theophylline and guaifenesin, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to theophylline and guaifenesin or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
The side effects of theophylline are more likely to occur in newborn infants, who are usually more sensitive to the effects of theophylline and guaifenesin.
Although there is no specific information about the use of guaifenesin in children, it is not expected to cause different side effects or problems in children than it does in adults.
Patients older than 60 years of age are likely to require a lower dose than younger adults. If the amount of theophylline is too high, side effects are more likely to occur. Your doctor may want to take blood samples to determine whether a dose change is needed.
Although there is no specific information about the use of guaifenesin in the elderly, it is not expected to cause different side effects or problems in older people than it does in younger adults.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.Theophylline
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking theophylline and guaifenesin, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using theophylline and guaifenesin with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using theophylline and guaifenesin with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Ethinyl Estradiol
- Peginterferon Alfa-2a
- Peginterferon Alfa-2b
Using theophylline and guaifenesin with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Interferon Alfa-2a
- St John's Wort
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using theophylline and guaifenesin with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use theophylline and guaifenesin, or give you special instructions about the use of food, alcohol, or tobacco.
Using theophylline and guaifenesin with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use theophylline and guaifenesin, or give you special instructions about the use of food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of theophylline and guaifenesin. Make sure you tell your doctor if you have any other medical problems, especially:
- Convulsions (seizures)—Theophylline may make this condition worse
- Heart failure or
- Liver disease or
- Underactive thyroid—The effects of theophylline may be increased
Proper use of theophylline and guaifenesin
Theophylline and guaifenesin works best when taken with a glass of water on an empty stomach (either 30 minutes to 1 hour before meals or 2 hours after meals) since that way it will get into the blood sooner. However, in some cases your doctor may want you to take theophylline and guaifenesin with meals or right after meals to lessen stomach upset. If you have any questions about how you should be taking theophylline and guaifenesin, check with your doctor.
Take theophylline and guaifenesin only as directed. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of serious side effects.
In order for theophylline and guaifenesin to help your medical problem, it must be taken every day in regularly spaced doses as ordered by your doctor . This is necessary to keep a constant amount of theophylline and guaifenesin in the blood. To help keep the amount constant, do not miss any doses.
Make certain your health care professional knows if you are on any special diet, such as a high-protein, low-carbohydrate or low-protein, high-carbohydrate diet.
The dose of theophylline and guaifenesin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of theophylline and guaifenesin. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
After you begin taking theophylline and guaifenesin combination, it is very important that your doctor check your blood level of theophylline at regular intervals to find out if your dose of theophylline and guaifenesin combination needs to be changed. Do not change your dose of theophylline and guaifenesin combination unless your doctor tells you to do so.
If you miss a dose of theophylline and guaifenesin, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using theophylline and guaifenesin
Your doctor should check your progress at regular visits, especially for the first few weeks after you begin taking theophylline and guaifenesin. A blood test may be taken to help your doctor decide whether the dose of theophylline and guaifenesin should be changed.
The theophylline in theophylline and guaifenesin may add to the central nervous system stimulant effects of caffeine-containing foods or beverages such as chocolate, cocoa, tea, coffee, and cola drinks. Avoid eating or drinking large amounts of these foods or beverages while taking theophylline and guaifenesin . If you have any questions about this, check with your doctor.
A change in your usual behavior or physical well-being may affect the way theophylline and guaifenesin works in your body. Check with your doctor if you:
- have a fever of 102 °F or higher for at least 24 hours or higher than 100 °F for longer than 24 hours.
- start or stop smoking.
- start or stop taking another medicine.
- change your diet for a long time.
Before you have myocardial perfusion studies (a medical test that shows how well blood is flowing to your heart), tell the medical doctor in charge that you are taking theophylline and guaifenesin. The results of the test may be affected by theophylline and guaifenesin.
Theophylline and guaifenesin side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Less common or rare
- Heartburn and/or vomiting
Symptoms of toxicity
- Abdominal pain, continuing or severe
- confusion or change in behavior
- convulsions (seizures)
- dark or bloody vomit
- dizziness or lightheadedness
- fast and/or irregular heartbeat, continuing
- nervousness or restlessness, continuing
- trembling, continuing
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Fast heartbeat
- increased urination
- trouble in sleeping
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about guaifenesin / theophylline
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