Dyphylline / Guaifenesin Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 28, 2025.

Applies to dyphylline / guaifenesin: oral tablet.

Get emergency medical help if you have any of these signs of an allergic reaction while taking dyphylline / guaifenesin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• pounding heartbeats or fluttering in your chest;

• rapid breathing, feeling short of breath;

• seizure (convulsions); or

• coughing up blood or vomit that looks like coffee grounds.

Common side effects may include:

• nausea, vomiting, stomach pain, diarrhea;

• headache;

• feeling restless or irritable;

• sleep problems (insomnia); or

• flushing (warmth, redness, or tingly feeling).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For healthcare professionals

Applies to dyphylline / guaifenesin: oral capsule, oral liquid, oral syrup, oral tablet.

Cardiovascular adverse events

• Frequency not reported: Cardiac palpitation^[Ref]

Nervous system

• Frequency not reported: Headache, CNS stimulation^[Ref]

Gastrointestinal

• Frequency not reported: Nausea^[Ref]

See also:

Further information

Dyphylline/guaifenesin 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.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer