Guaifenesin / Pseudoephedrine Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 23, 2024.

Applies to guaifenesin / pseudoephedrine: oral capsule, oral tablet, oral tablet extended release 12 hour.

Serious side effects

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.

Other side effects

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 any of these side effects or any other side effects bother you or do not go away:

• Dizziness.
• Feeling nervous and excitable.
• Not able to sleep.

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/pseudoephedrine: oral capsule, oral capsule extended release, oral liquid, oral syrup, oral tablet, oral tablet chewable, oral tablet extended release.

Cardiovascular

• Frequency not reported: Tachycardia, palpitations, other cardiac dysrhythmias, hypertension^[Ref]

Nervous system

• Frequency not reported: Headache, dizziness, tremor, excitability^[Ref]

Psychiatric

• Frequency not reported: Irritability, tolerance and dependence (with prolonged pseudoephedrine administration), anxiety, restlessness, insomnia, hallucinations (particularly in children), paranoid delusions, sleep disturbance^[Ref]

Hypersensitivity

• Frequency not reported: Hypersensitivity reactions, cross-sensitivity with other sympathomimetics^[Ref]

Genitourinary

• Frequency not reported: Difficulty in micturition (including urinary retention)^[Ref]

Dermatologic

• Frequency not reported: Skin reactions (including rash, sweating), severe skin reactions including acute generalized exanthematous pustulosis (AGEP)^[Ref]

Gastrointestinal

• Frequency not reported: Nausea, vomiting, gastrointestinal discomfort, dry mouth^[Ref]

Musculoskeletal

• Frequency not reported: Muscular weakness^[Ref]

Metabolic

• Frequency not reported: Thirst^[Ref]

Further information

Guaifenesin/pseudoephedrine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer