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Acetylcysteine Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 2, 2023.

Applies to acetylcysteine: oral capsule, oral solution, oral tablet. Other dosage forms:

Serious side effects of Acetylcysteine

Along with its needed effects, acetylcysteine 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

Other side effects of Acetylcysteine

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

For Healthcare Professionals

Applies to acetylcysteine: compounding powder, inhalation solution, intravenous solution, oral capsule, 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]

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]

Gastrointestinal

Very common (10% or more): Vomiting NOS (12%)

Common (1% to 10%): Nausea

Frequency not reported: Stomatitis[Ref]

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]

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]

Cardiovascular

Common (1% to 10%): Tachycardia

Uncommon (0.1% to 1%): Hypotension

Frequency not reported: Cyanosis, tachycardia, bradycardia, cardiac arrest, extrasystoles, flushing, hypertension, vasodilation, ECG changes[Ref]

Dermatologic

Common (1% to 10%): Urticaria/facial flushing, rash NOS, pruritus, flushing

Frequency not reported: Angioedema, sweating, edema periorbital, clamminess[Ref]

Metabolic

Common (1% to 10%): Edema

Frequency not reported: Acidosis, hypokalemia[Ref]

Other

Rare (less than 0.1%): Death

Frequency not reported: Fever, malaise, rigors, chest pain, facial pain, facial edema, raised temperature[Ref]

Nervous system

Frequency not reported: Syncope, generalized seizure, drowsiness[Ref]

Local

Frequency not reported: Injection site reaction[Ref]

Musculoskeletal

Frequency not reported: Arthralgia, arthropathy[Ref]

Hepatic

Frequency not reported: Deterioration of liver function[Ref]

Hematologic

Frequency not reported: Thrombocytopenia[Ref]

Ocular

Frequency not reported: Blurred vision, eye pain, puffy eyes, itching/redness/irritation in eyes (ophthalmic formulation)[Ref]

Psychiatric

Frequency not reported: Anxiety[Ref]

Frequently asked questions

References

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

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

3. Cerner Multum, Inc. Australian Product Information.

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

Further information

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.

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