Note: This document contains side effect information about acetaminophen / dextromethorphan / triprolidine. Some dosage forms listed on this page may not apply to the brand name Mucinex Nightshift Cold & Flu.

Applies to acetaminophen / dextromethorphan / triprolidine: oral liquid.

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

In rare cases, acetaminophen may cause a severe skin reaction that can be fatal. This could occur even if you have taken acetaminophen in the past and had no reaction. Stop taking this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling. If you have this type of reaction, you should never again take any medicine that contains acetaminophen.

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

• any new or worsening symptoms;

• nervousness, dizziness, or drowsiness;

• fever for longer than 3 days;

• redness, swelling, or rash;

• ongoing headache; or

• pain, cough, or sinus congestion lasting more than 7 days.

Some side effects may be more likely in older adults.

Common side effects may include:

• dizziness, drowsiness;

• dry mouth, nose, or throat;

• blurred vision;

• constipation;

• feeling restless or excited (especially in children); or

• sleep problems (insomnia).

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