Skip to main content

NAC Side Effects

Generic name: acetylcysteine

Medically reviewed by Drugs.com. Last updated on Aug 4, 2024.

Note: This document provides detailed information about NAC Side Effects associated with acetylcysteine. Some dosage forms listed on this page may not apply specifically to the brand name NAC.

Applies to acetylcysteine: oral capsule, oral solution, oral tablet.

Other dosage forms:

Common side effects of NAC

Some side effects of acetylcysteine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Serious side effects of NAC

Along with its needed effects, acetylcysteine (the active ingredient contained in NAC) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking acetylcysteine:

Incidence not known

  • difficulty with breathing or swallowing
  • fever
  • hives or itching
  • nausea
  • rash with or without a fever
  • reddening of the skin, especially around the ears
  • severe or ongoing vomiting
  • swelling of the eyes, face, or inside of the nose
  • unusual tiredness or weakness

For healthcare professionals

Applies to acetylcysteine: compounding powder, inhalation solution, intravenous solution, oral capsule, oral powder for reconstitution, oral tablet, oral tablet effervescent.

General

The most common adverse events were anaphylactoid reaction, nausea, vomiting, flushing, and skin rash.[Ref]

Hypersensitivity

Anaphylactoid symptoms include airway obstruction (bronchospasm), angioedema, dyspnea, hypotension, shock, tachycardia, urticaria, and injection site reaction (including rash). These are most common either during, or at the end of the loading dose infusion, and may be dose related. Careful monitoring is recommended.[Ref]

Gastrointestinal

Respiratory

Respiratory symptoms were defined as presence of any of the following: cough, wheezing, stridor, shortness of breath, chest tightness, respiratory distress, or bronchospasm.[Ref]

Cardiovascular

Dermatologic

Metabolic

Other

Nervous system

Local

Musculoskeletal

Hepatic

Hematologic

Ocular

Psychiatric

References

1. (2004) "Product Information. Acetadote (acetylcysteine)." Cumberland-Swan Inc

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

4. (2015) "Product Information. Acetylcysteine (acetylcysteine)." American Regent Laboratories Inc

Frequently asked questions

Further information

NAC 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.