Guaifenesin
Guaifenesin (gwye FEN eh sin) is a generic over-the-counter (OTC) medication used to help loosen mucus in your airway so that you can cough it up. Guaifenesin belongs to a group of drugs called expectorants.
Guaifenesin (gwye FEN eh sin) is a generic over-the-counter (OTC) medication used to help loosen mucus in your airway so that you can cough it up. Guaifenesin belongs to a group of drugs called expectorants.
- Brand
- • Powder
- • Powder
- • 20 gm
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Intro
Introduction
Written by Melanie Sangobowale PharmD
Medically reviewed by Alex Brewer, PharmD, MBA
Updated on October 5, 2023
Guaifenesin (gwye FEN eh sin) is a generic over-the-counter (OTC) medication used to help loosen mucus in your airway so that you can cough it up. Guaifenesin belongs to a group of drugs called expectorants.
Since guaifenesin is an OTC drug, you do not need a prescription to purchase it.
Side effects
Side effects of guaifenesin
Guaifenesin may cause mild or serious side effects. More common mild side effects of guaifenesin and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.
To learn more about guaifenesin’s side effects, ask your doctor or pharmacist. You can also refer to the Drug Facts label for guaifenesin listed in the “Resources” section.
Mild side effects
More common mild side effects reported with guaifenesin extended-release (ER)* oral tablet are listed below.
This article doesn’t include all possible mild side effects of the drug. To learn more about guaifenesin’s side effects refer to the Drug Facts label for guaifenesin listed in the “Resources” section.
With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.
Guaifenesin ER oral tablet’s mild side effects include:
- nausea
- vomiting
- diarrhea
- abdominal pain
- mild allergic reaction†
* With extended release, the drug is released slowly over time in your body.
† For details about this side effect, see the “Interactions and warnings for guaifenesin” section.
Serious side effects
A serious side effect of guaifenesin ER oral tablet is listed below.
This article doesn’t include all possible serious side effects of the drug. To learn more about guaifenesin’s side effects, refer to the Drug Facts label for guaifenesin listed in the “Resources” section.
With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.
In general, guaifenesin’s serious side effects include severe allergic reaction. For details about this side effect, see the “Interactions and warnings for guaifenesin” section.
FAQ
Common questions about guaifenesin
Below you’ll find answers to a few commonly asked questions about guaifenesin.
Is guaifenesin available as an oral syrup?
Yes, guaifenesin is available over the counter (OTC) as an oral liquid solution, also known as an oral syrup. (You do not need a prescription to purchase OTC drugs.) Guaifenesin oral syrup is used in adults and children ages 2 years and older.
The dosages of guaifenesin oral syrup are based on age. Each OTC product may have different directions. This is because there are many different manufacturers that make OTC guaifenesin oral syrup. Ensure to read each product label carefully so that you’re taking the correct dose. You can also ask your doctor or pharmacist for the dosage that’s best for you.
If you have questions about the available forms of guaifenesin, talk with your doctor or pharmacist.
What brand names are available for guaifenesin?
Guaifenesin extended-release tablets are available as the brand name Mucinex. (With extended release, the drug is released slowly over time in your body.)
Another brand name of guaifenesin includes Mucinex Mini-Melts, which come as granules. (Granules are sprinkled on the tongue so they can melt.)
A generic medication is an identical copy of the active drug in a brand-name medication. (An active drug is the ingredient that makes a medication work.) Generic drugs are believed to be as effective and safe as brand-name drugs. And generic drugs typically cost less compared to brand-name drugs.
If you have more questions, talk with your doctor or pharmacist.
How does guaifenesin work? And how long does it take to start working?
Guaifenesin belongs to a class of drugs called expectorants. It works by thinning and loosening mucus in your airways. It does this by increasing the amount of water in the mucus. This allows the mucus to thin out so you can cough it up. Doing this will help clear your airways, making it easier to breathe.
It takes about 1 hour for you to notice a relief in symptoms after taking guaifenesin.
If you’d like to know more about this, talk with your doctor or pharmacist.
Uses
Uses of guaifenesin
The Food and Drug Administration (FDA) approves OTC drugs such as guaifenesin for certain conditions. The approved use for guaifenesin is described below.
Use for loosening mucus in airway
Doctors may prescribe or recommend guaifenesin extended-release* oral tablet to help loosen mucus in your airway. It’s used for this purpose in adults and children over ages 12 years. It’s usually taken as a short-term treatment.
Mucus can buildup in your airway due to asthma, allergies, and infections, such as the common cold. Lung conditions, such as chronic obstructive pulmonary disease, can also cause mucus buildup. Guaifenesin helps loosen mucus so that you can cough it up. This helps you breathe easier.
To learn more about the different forms of guaifenesin, talk with your doctor or pharmacist.
* With extended release, the drug is released slowly over time in your body.
Interactions and warnings
Interactions and warnings for guaifenesin
Below, you’ll find information about guaifenesin’s possible interactions and warnings.
Interactions of guaifenesin
Guaifenesin isn’t known to interact with any medications or supplements. (Interactions can affect how a drug works.) But this doesn’t mean drug interactions with guaifenesin won’t happen or be reported sometime. For instance, medications created at a later time could interact with guaifenesin.
Because of this, you should ask your doctor and pharmacist about possible interactions with guaifenesin. They can check for any interactions that may affect you, such as those with:
- vaccines
- foods or alcohol
- other drugs
Warnings for guaifenesin
Some people should not take guaifenesin, and others should take it cautiously.
Guaifenesin could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether guaifenesin is a safe option for you. These warnings may differ based on the form of guaifenesin you take.
Ask your doctor about specific warnings for guaifenesin, and be sure to tell your doctor about your:
- current health, including any allergies to medications
- past health conditions or surgeries
Allergic reaction
Guaifenesin can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.
If you’ve had an allergic reaction to guaifenesin or any of its ingredients, your doctor will likely not prescribe or recommend guaifenesin. They can tell you about medications that are safer options for you.
A mild allergic reaction may cause the following symptoms:
A severe allergic reaction may cause the following symptoms:
- swelling under your skin, usually in your hands, feet, eyelids, or lips
- swelling of your mouth, throat, or tongue, which can cause breathing problems
If you have an allergic reaction to guaifenesin, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.
Overdose of guaifenesin
If you take guaifenesin by mouth, you should not take more guaifenesin than your doctor prescribes or recommends. For some drugs, doing so may lead to harmful effects or overdose.
If you think you’ve taken too much guaifenesin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.
Pregnancy or breastfeeding and guaifenesin
Information about guaifenesin and pregnancy and breastfeeding is described below.
Guaifenesin and pregnancy
It’s not known whether guaifenesin should be taken during pregnancy. But your doctor may recommend you avoid taking guaifenesin during your first trimester. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.
Guaifenesin and breastfeeding
It’s not known whether guaifenesin should be taken while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before taking this medication.
Ask your doctor
What to ask your doctor
Let your doctor know if you have questions about guaifenesin or would like more details about it.
Here’s a list of some possible questions you may want to ask your doctor:
Resources
Resources
- Albrecht HH, et al. (2017). Role of guaifenesin in the management of chronic bronchitis and upper respiratory tract infections. https://doi.org/10.1186/s40248-017-0113-4
- Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
- Guaifenesin solution. (2022). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c2e53fb5-2798-47c8-9285-d1077d46e629
- Guaifenesin tablet, extended release. (2016). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/51a35002-77ba-47e5-93ab-3f28242d16b6/spl-doc
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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