Guaifenesin Side Effects

Possible side effects of guaifenesin are listed below. Contact your doctor or pharmacist for medical advice about side effects if they are severe or do not go away in a few days.

• Headache
• Nausea
• Vomiting

Rarely, guaifenesin can cause an unusual or allergic reaction. Signs and symptoms of allergic reactions can include skin rash, swelling, and difficulty breathing. Contact your healthcare provider right away or seek emergency medical attention if you experience high fever, skin rash, a headache that does not get better, swelling of the lips or tongue, or difficulty breathing.

The above list may not include all the potential side effects of guaifenesin. Tell your doctor if you have any unusual side effects or if they do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Guaifenesin Overdose: In case of a known or suspected overdose of guaifenesin, contact your doctor immediately or call the local poison control center or provincial poison control center in your area. You can also call the national poison control center at 1-800-222-1222. If a person has collapsed, cannot breathe, or has had a seizure, call 911.

Source: FDA