Acetylcysteine Solution Side Effects Center

Last updated on RxList: 7/19/2021
Acetylcysteine Solution Side Effects Center

What Is Mucomyst (Acetylcysteine Solution)?

Mucomyst (Acetylcysteine Solution n-acetyl-l-cysteine) is a solution of a naturally occurring amino acid that is used to help clear mucus (acts as a mucolytic agent) and material entrapped in mucus in people that have thick mucus that may interfere with breathing or other functions. For example, Mucomyst (Acetylcysteine Solution) may be used to help clear mucus in COPD, cystic fibrosis, pneumonia, and in tracheostomy care. Mucomyst (Acetylcysteine Solution) may also be used as an antidote for acetaminophen toxicity. Mucomyst (Acetylcysteine Solution) is available as a generic.

What Are Side Effects of Mucomyst (Acetylcysteine Solution)?

Common side effects of Mucomyst (Acetylcysteine Solution) include:

  • inflammation of the mouth,
  • nausea,
  • vomiting,
  • fever,
  • runny nose,
  • drowsiness,
  • clamminess,
  • chest tightness,
  • coughing,
  • wheezing, or
  • shortness of breath.

Serious side effects of Mucomyst (Acetylcysteine Solution) may include:

  • chest tightness,
  • bronchoconstriction, and
  • bleeding.

Dosage for Mucomyst (Acetylcysteine Solution)

When nebulized into a face mask, mouthpiece, or tracheostomy, 1 to 10 mL of the 20% Mucomyst (Acetylcysteine Solution) or 2 to 20 mL of the 10% solution may be given every 2 to 6 hours; the recommended dose of Mucomyst (Acetylcysteine Solution) for most patients is 3 to 5 mL of the 20% solution or 6 to 10 mL of the 10% solution three to four times a day.

What Drugs, Substances, or Supplements Interact with Mucomyst (Acetylcysteine Solution)?

Mucomyst (Acetylcysteine Solution) may interact with other drugs. Tell your doctor all medications and supplements you use.

Mucomyst (Acetylcysteine Solution) During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before treatment with Mucomyst (Acetylcysteine Solution); it is unknown if it would affect a fetus. It is unknown if Mucomyst (Acetylcysteine Solution) passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Mucomyst (Acetylcysteine Solution), USP (n-acetyl-l-cysteine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Acetylcysteine Solution Consumer Information

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

Call your doctor at once if you have:

  • severe or ongoing vomiting;
  • coughing up blood or vomit that looks like coffee grounds; or
  • signs that the medicine may not be working--upper stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

  • nausea, vomiting, upset stomach;
  • rash; or
  • fever.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Acetylcysteine Solution Professional Information



Adverse effects have included stomatitis, nausea, vomiting, fever, rhinorrhea, drowsiness, clamminess, chest tightness and bronchoconstriction. Clinically overt acetylcysteine induced bronchospasm occurs infrequently and unpredictably even in patients with asthmatic bronchitis or bronchitis complicating bronchial asthma.

Acquired sensitization to acetylcysteine has been reported rarely. Reports of sensitization in patients have not been confirmed by patch testing. Sensitization has been confirmed in several inhalation therapists who reported a history of dermal eruptions after frequent and extended exposure to acetylcysteine.

Reports of irritation to the tracheal and bronchial tracts have been received and although hemoptysis has occurred in patients receiving acetylcysteine such findings are not uncommon in patients with bronchopulmonary disease and a causal relationship has not been established.


Oral administration of acetylcysteine, especially in the large doses needed to treat acetaminophen overdose, may result in nausea, vomiting and other gastrointestinal symptoms. Rash with or without mild fever has been observed rarely.

Read the entire FDA prescribing information for Acetylcysteine Solution (N-acetyl-L-cysteine)

© Acetylcysteine Solution Patient Information is supplied by Cerner Multum, Inc. and Acetylcysteine Solution Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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