NAC Side Effects
Generic name: acetylcysteine
Medically reviewed by Drugs.com. Last updated on Sep 12, 2021.
Note: This document contains side effect information about acetylcysteine. Some of the dosage forms listed on this page may not apply to the brand name NAC.
For the Consumer
Applies to acetylcysteine: oral capsule, oral powder, oral solution
Other dosage forms:
Side effects requiring immediate medical attention
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
- hives or itching
- 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
Side effects not requiring immediate medical attention
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:
- Mild nausea
- stomach upset
For Healthcare Professionals
Applies to acetylcysteine: compounding powder, inhalation solution, intravenous solution, oral capsule, oral tablet, oral tablet effervescent
The most common adverse events were anaphylactoid reaction, nausea, vomiting, flushing, and skin rash.[Ref]
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]
Very common (10% or more): Anaphylactoid reaction (18%)
Uncommon (0.1% to 1%): Anaphylaxis
Rare (less than 0.1%): Acquired sensitization
Frequency not reported: Dermal eruptions[Ref]
Very common (10% or more): Vomiting NOS (12%)
Common (1% to 10%): Nausea
Respiratory symptoms were defined as presence of any of the following: cough, wheezing, stridor, shortness of breath, chest tightness, respiratory distress, or bronchospasm.[Ref]
Common (1% to 10%): Respiratory symptoms, pharyngitis, rhinorrhea, rhonchi, throat tightness
Frequency not reported: Bronchoconstriction, bronchospasm, irritation to tracheal and bronchial tract (inhalation route), hemoptysis, dyspnea, respiratory arrest, coughing, stridor[Ref]
Common (1% to 10%): Tachycardia
Uncommon (0.1% to 1%): Hypotension
Common (1% to 10%): Urticaria/facial flushing, rash NOS, pruritus, flushing
Common (1% to 10%): Edema
Rare (less than 0.1%): Death
Frequency not reported: Fever, malaise, rigors, chest pain, facial pain, facial edema, raised temperature[Ref]
Frequency not reported: Injection site reaction[Ref]
Frequency not reported: Arthralgia, arthropathy[Ref]
Frequency not reported: Deterioration of liver function[Ref]
More about NAC (acetylcysteine)
Related treatment guides
1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
2. "Product Information. Acetadote (acetylcysteine)." Cumberland-Swan Inc, Smyrna, TN.
3. Cerner Multum, Inc. "Australian Product Information." O 0
4. "Product Information. Acetylcysteine (acetylcysteine)." American Regent Laboratories Inc, Shirley, NY.
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.