From the FDA Drug Label
CONTRAINDICATIONS Acetylcysteine is contraindicated in those patients who are sensitive to it.
The contraindication for Mucomyst (acetylcysteine) is:
- Hypersensitivity to the drug, as it is contraindicated in patients who are sensitive to it 1.
From the Research
Acetylcysteine (Mucomyst) is contraindicated in patients with a known hypersensitivity to the drug, and its use should be approached with caution in patients with asthma, history of bronchospasm, severe respiratory insufficiency, and those with hepatic or renal impairment. The contraindications and precautions for Mucomyst are based on its potential to cause adverse reactions, including anaphylactoid reactions, which can be severe and life-threatening 2.
Key Considerations
- Patients with a history of asthma or bronchospasm are at increased risk of adverse reactions, including bronchospasm, when treated with acetylcysteine 3, 2.
- Severe respiratory insufficiency may be exacerbated by acetylcysteine administration, particularly when given via nebulization, as it can increase bronchial secretions 3.
- Elderly patients and those with hepatic or renal impairment should be treated with caution due to potential alterations in drug metabolism and excretion 4.
- Acetylcysteine is generally not recommended during pregnancy unless clearly necessary, and caution should be exercised when administering it to nursing mothers, due to limited data on its safety in these populations 4.
Adverse Reactions
- Common adverse reactions to acetylcysteine include nausea, vomiting, stomatitis, fever, rhinorrhea, drowsiness, and bronchospasm in susceptible individuals 3, 2.
- Anaphylactoid reactions, which can be severe, have been reported with acetylcysteine use, particularly in patients with a history of allergy or atopy 2.
Administration Considerations
- When used as an oral solution, patients with peptic ulcers or esophageal varices should use acetylcysteine with caution due to its potential to irritate the gastrointestinal mucosa 4.
- Nebulization of acetylcysteine can increase bronchial secretions, potentially worsening respiratory conditions in certain patients, and should be used with caution in patients with severe respiratory disease 3.