Guaifenesin extended-release oral tablet side effects: A detailed guide

This article describes possible side effects of guaifenesin extended-release (ER)* oral tablet. You’ll also find information on cost savings and coupon options for guaifenesin. To learn more about guaifenesin, including the drug’s uses, side effects, ways to save on cost, and more, talk with your doctor or pharmacist.

Guaifenesin ER oral tablet is a generic version of the brand-name drug Mucinex.

*Extended-release (ER) medications release their contents into your body slowly over some time.

More common side effects of guaifenesin

Guaifenesin ER oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.

Commonly reported side effects of guaifenesin ER oral tablet include:

• dizziness
• headache*
• indigestion*

* To learn more about this side effect, see the “Side effects of guaifenesin in detail” section below.

Mild side effects of guaifenesin

Guaifenesin ER oral tablet may cause certain mild side effects. Most often, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.

Mild side effects of guaifenesin ER oral tablet that occurred in studies include:

• dizziness
• headache
• indigestion
• nausea and vomiting
• mild allergic reaction *†

Guaifenesin ER oral tablet may cause more mild side effects than those listed above. For details, talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Side effects of guaifenesin in detail” section below.
† An allergic reaction is possible with guaifenesin extended-release (ER) oral tablet. But it wasn’t reported in the drug’s studies.

Serious side effects of guaifenesin

Guaifenesin ER oral tablet may cause certain serious side effects. If you have any serious side effects from guaifenesin ER oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.

After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with guaifenesin.

Serious side effects of guaifenesin ER oral tablet that are possible include severe allergic reaction. A possible serious side effect of guaifenesin ER oral tablet is a severe allergic reaction. But this wasn’t reported in the drug’s studies.

Common questions about side effects of guaifenesin

Here are answers to some common questions about the side effects of guaifenesin ER oral tablet. If you have other questions, talk with your doctor or pharmacist.

Is guaifenesin safe for older adults?

Yes, it’s believed that guaifenesin is safe for older adults to take. Different side effects haven’t been reported in older adults taking guaifenesin compared to younger adults. In general, “older adults” refers to people ages 65 years and older.

As you age, your organs may slowly stop working as well as they used to. This can affect whether certain medications are safe to take. For example, having a kidney or liver condition can affect your body’s ability to break down a medication and get rid of it after you take a dose. This can raise your risk of side effects. That said, this isn’t expected to be an issue with guaifenesin.

Talk with your doctor or pharmacist if you’d like to learn more about whether guaifenesin is safe for you to take.

Does guaifenesin cause long-term side effects?

No, long-term side effects aren’t expected with guaifenesin ER oral tablet. In studies, specific side effects weren’t seen in people who had taken the drug for a long time. Long lasting side effects after treatment ended also weren’t reported.

Talk with your doctor if you have questions about possible long-term side effects with guaifenesin. They can offer advice based on your health history.

Coupon for guaifenesin

Visit this page to access Optum Perks coupons and get price estimates for guaifenesin when you use the coupons. These coupons can provide significant savings on your prescription costs. 

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Side effects of guaifenesin in detail

Below you’ll find details on some of the side effects of guaifenesin ER oral tablet.

Headache

In studies, headache was common in people taking guaifenesin ER oral tablet. This side effect is usually mild.

Symptoms of headache can include:

• a constant, dull ache on both sides of your head
• pain that spreads to or from your neck
• feeling as if you have a tight band around your head

It’s important to note that having an infection or cough can lead to a headache. Guaifenesin is often recommended to thin and clear mucus in the chest, which is often caused by an infection.

Ways to manage

If you experience symptoms of headache, tell your doctor. They’ll likely recommend a treatment, such as acetaminophen (Tylenol). Guaifenesin is typically used short term, and the headache should go away once treatment is stopped.

Indigestion

In studies, indigestion was rare in people using guaifenesin ER oral tablet. This side effect was reported in people who took higher than recommended doses of guaifenesin. This side effect is usually mild.

Indigestion happens when your body doesn’t digest food properly. Symptoms can include:

• heartburn
• nausea and vomiting
• bloating in your abdomen

Ways to manage

If you experience symptoms of indigestion, tell your doctor. They’ll likely recommend a treatment. This can include home remedies for indigestion, such as avoiding foods that trigger symptoms and eating slowly. They may also suggest using a medication to treat your symptoms, such as famotidine (Pepcid). Indigestion related to guaifenesin typically goes away once you complete treatment, and the drug is usually used short term.

Allergic reaction

For some people, guaifenesin ER oral tablet can cause an allergic reaction. This side effect wasn’t reported in the drug’s studies but may still occur.

Symptoms can be mild or serious, and they may include:

• itchiness
• skin rash
• swelling under the skin, usually affecting eyelids, lips, hands, or feet
• swelling of the mouth, tongue, or throat, which can make it hard to breathe
• flushing (temporary warmth, redness, or deepening of skin color)

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to guaifenesin ER oral tablet, your doctor may recommend taking a different medication instead.

Warnings for guaifenesin

Below are some factors you may want to discuss with your doctor before taking guaifenesin ER oral tablet.

Warnings

It may not be safe for you to take guaifenesin ER oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether guaifenesin ER oral tablet is a safe treatment option for you.

Before taking guaifenesin ER oral tablet, tell your doctor about your health and medications you take. Things to consider include:

• asthma
• chronic bronchitis or emphysema
• past allergic reaction to guaifenesin

Guaifenesin and pregnancy

It’s not known whether guaifenesin ER oral tablet should be taken during pregnancy. 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 ER oral tablet should be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before using this medication.

Guaifenesin and alcohol

Guaifenesin ER oral tablet is not known to interact with alcohol.

If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with guaifenesin ER oral tablet.

What to ask your doctor

This article describes common and serious side effects of guaifenesin ER oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.

Here’s a list of some possible questions you may want to ask your doctor:

• Does my health history raise my risk of side effects if I take guaifenesin ER oral tablet?
• Do any medications I take interact with guaifenesin ER oral tablet and raise my risk of side effects?
• Are there any alternative medications that I can take for my condition?

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.