Applies to guaifenesin: oral liquid, oral packet, oral solution, oral syrup, oral tablet, oral tablet extended release 12 hour.

Serious side effects of Guaifenesin

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Cough that does not go away.

Other side effects of Guaifenesin

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if you have any side effects that bother you or do not go away.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

For Healthcare Professionals

Applies to guaifenesin: compounding powder, oral capsule, oral capsule extended release, oral granule, oral liquid, oral solution, oral tablet, oral tablet extended release.

General

Guaifenesin has been generally well tolerated.^[Ref]

Gastrointestinal

Gastrointestinal side effects have included stomach upset and vomiting with higher than recommended doses. Doses recommended for expectoration have rarely been associated with gastrointestinal upset.^[Ref]

Nervous system

Nervous system side effects have occasionally included dizziness and headache.^[Ref]

Dermatologic

Dermatologic side effects have included rare reports of rash.^[Ref]

Hypersensitivity

Hypersensitivity side effects have included a report of an anaphylactic reaction.^[Ref]