Z-COF 12 Side Effects

Generic name: dextromethorphan / guaifenesin / pseudoephedrine

Medically reviewed by Drugs.com. Last updated on Jun 9, 2025.

Note: This document provides detailed information about Z-COF 12 Side Effects associated with dextromethorphan / guaifenesin / pseudoephedrine. Some dosage forms listed on this page may not apply specifically to the brand name Z-COF 12.

Applies to dextromethorphan / guaifenesin / pseudoephedrine: oral liquid, oral tablet, oral tablet extended release.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have:

• fast or uneven heart rate;

• severe dizziness or anxiety, feeling like you might pass out;

• severe headache;

• mood changes;

• fever; or

• dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, chest pain, uneven heartbeats, seizure).

Common side effects may include:

• diarrhea;

• dizziness, drowsiness;

• sleep problems (insomnia); or

• feeling nervous, restless, or irritable.

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

See also:

For healthcare professionals

Applies to dextromethorphan/guaifenesin/pseudoephedrine: oral capsule, oral liquid, oral suspension, oral suspension extended release, oral syrup, oral tablet, oral tablet extended release.

General adverse events

The manufacturer has not provided adverse event information.^[Ref]

Further information

Z-COF 12 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