NAC Side Effects
Generic Name: acetylcysteine
Note: This page contains side effects data for the generic drug acetylcysteine. It is possible that some of the dosage forms included below may not apply to the brand name NAC.
It is possible that some side effects of NAC may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
For the Consumer
Applies to acetylcysteine: inhalation solution
As well as its needed effects, acetylcysteine (the active ingredient contained in NAC) may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking acetylcysteine, check with your doctor or nurse as soon as possible:Less common
- Wheezing, tightness in chest, or difficulty in breathing (especially in asthma patients)
- Skin rash or other irritation
Some acetylcysteine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:Less common
- Clammy skin
- increase in amount of mucus in lungs
- irritation or soreness of mouth, throat, or lungs
- nausea or vomiting
- runny nose
For patients using a face mask for inhalation of acetylcysteine: the mask may leave a stickiness on your face. This can be removed with water.
When you use acetylcysteine, you may notice that the medicine has an unpleasant odor at first. However, this smell will go away soon after you use the medicine.
For Healthcare Professionals
Applies to acetylcysteine: compounding powder, inhalation solution, intravenous solution, oral capsule, oral tablet
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
Frequency not reported: Stomatitis[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]
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%): Tachycardia
Uncommon (0.1% to 1%): Hypotension
Frequency not reported: Cyanosis, tachycardia, bradycardia, cardiac arrest, extrasystoles, flushing, hypertension, vasodilation, ECG changes[Ref]
Common (1% to 10%): Urticaria/facial flushing, rash NOS, pruritus, flushing
Frequency not reported: Angioedema, sweating, edema periorbital, clamminess[Ref]
Common (1% to 10%): Edema
Frequency not reported: Acidosis, hypokalemia[Ref]
Rare (less than 0.1%): Death
Frequency not reported: Fever, malaise, rigors, chest pain, facial pain, facial edema, raised temperature[Ref]
Frequency not reported: Syncope, generalized seizure, drowsiness[Ref]
Frequency not reported: Injection site reaction[Ref]
Frequency not reported: Arthralgia, arthropathy[Ref]
Frequency not reported: Deterioration of liver function[Ref]
Frequency not reported: Thrombocytopenia[Ref]
Frequency not reported: Blurred vision, eye pain, puffy eyes, itching/redness/irritation in eyes (ophthalmic formulation)[Ref]
Frequency not reported: Anxiety[Ref]
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.
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