Acetylcysteine (Inhalation)

Here is a detailed look at Acetylcysteine, inhalation route, a drug that is administered to dissolve or destroy mucus.


Acetylcysteine has been given the brand name 'Mucomyst' in the U.S. It belongs to the chemical class of amino acids and the therapeutic class mucolytic. It is designated for lung conditions where an accumulation of mucus causes breathing difficulties.

Acetylcysteine dissolves or thins the mucus so that it can easily be coughed out. In cases where the patient is unable to cough out the mucus, it is sucked out using suction. It is a prescription-only medicine.

It was patented in 1960, and licensed for use in 1968. The World Health Organization has listed Acetylcysteine in its list of essential medicines as one of the safest and most effective medications needed in a health system.

It is available as a solution and is administered by inhalation. In hospitals, however, it can be given in other ways such as by injection or orally.

Conditions Treated

  • Tracheostomy care
  • Post-traumatic conditions in the chest
  • Use during anesthesia
  • Pulmonary complications that affect cystic fibrosis
  • Pulmonary complications that are associated with surgery
  • Diagnostic bronchial studies (bronchospirometry, bronchial wedge catheterization, and bronchograms)
  • Atelectasis arising due to obstruction of mucus
  • Acute bronchopulmonary disease (tracheobronchitis, pneumonia, and bronchitis)
  • Chronic bronchopulmonary illness (emphysema with bronchitis, chronic emphysema, tuberculosis, chronic asthmatic bronchitis, primary (major) amyloidosis of the lungs and bronchiectasis)

Type of Medicine

  • Mucolytic

Side Effects

Acetylcysteine inhalation route is a safe drug that is well-tolerated. It may, however, have some undesirable effects, some of which may require immediate medical attention. All the severe side effects are seldom observed. Medical care should be sought immediately if you notice the following symptoms.

  • A feeling of tightness in the chest, wheezing or difficulty breathing. These symptoms should be considered particularly severe if presented by an asthma patient. This side effect is observed very rarely.
  • Rashes on the skin and other irritations. This as well is quite rare.

There are other side effects of this drug that may not require medical attention but which go away with continued use. The patient's body adjusts to the medicine with time, and this is why these side effects go away.

See a medical professional if these side effects become bothersome and the patient would like to find ways to reduce the symptoms or prevent them all together.

These side effects are also quite uncommon. They are the following:

  • Runny nose
  • Nausea with or without vomiting
  • Fever
  • Clammy skin
  • Increase of the amount of mucus in the lungs
  • Soreness or irritation in the throat, mouth, or lungs
  • Patients may experience stickiness on the face after using a face mask to inhale Acetylcysteine. The adhesiveness can be removed with water.
  • The patient may find that the drug has an unpleasant odor initially. This goes away soon after using the medicine.


Mucomyst is available in glass vials which are rubber stoppered containing 4, 10 or 30mls of the drug solution. It comes as a 10% or 20% solution. While the 10% solution may be used undiluted, the 20% solution may be diluted with sodium chloride or sterile water.

The sterile solution of Mucomyst must be handled carefully to avoid contamination as it does come with a microbial agent. Every opened vial must be stored in the fridge and used within 96 hours.


When mucomyst is nebulized into tracheostomy, mouthpiece, or face mask, the following volumes are used.

  • 2 to 20ml of the 10% solution or 1 to 10 mL of the 20% solution, administered every 2 to 6 hours.
  • For most patients, the recommended dosage is as follows: 6 to 10mL of the 10% solution or 3 to 5mL of the 20% solution given 3 to 4 times per day.


The recommended dose here is the volume of 10% or 20% of mucomyst solution that will maintain and retain a heavy mist in the croupette or tent for the period desired. For this kind of administration, large volumes, as much as 300mL for a single treatment are needed. The desirable periods of treatment may be intermittent and continuous such as overnight.

As this kind of treatment is administered, nebulization into croupette or a tent must be individualized. The equipment available must be taken into account.

Note: A compressed air tank or an air compressor is used to provide pressure to nebulize the solution. Oxygen can be used, but this should be done with precaution for patients with CO2 retention and severe respiratory disease.


For adults and children, the following dosages are used.

2 to 4 mL of 10% solution or 1 to 2mL of 20% solution should be given by inhalation or directly placed in trachea 2 to 3 times before the test.

Missed Dose

A double dose of acetylcysteine should never be taken. If for some reason a dose is missed, it should be taken as soon as possible. If however, the missed treatment can only be taken too close to the time to get another dose, it should be skipped altogether.


Mucomsyt should be given using nebulizers made of plastic or glass. Specific materials used to make nebulization equipment such as iron, copper, and rubber react with acetylcysteine. Acceptable materials which do not react with acetylcysteine should be used to make the nebulization equipment. These are materials such as glass, anodized aluminum, plastic, chromed metal, aluminum, sterling silver, tantalum, or stainless steel.

There are numerous nebulizers available in the market that are made of safe materials and that deliver mucomyst nebulae acceptably.

The apparatus used to administer mucomyst should be able to deliver it as fine nebulae. Nebulizers that are available in the market produce mucomyst nebulae that are satisfactory for retention in the respiratory tract.

The nebulized solution is breathed in from the nebulizer. A plastic face or mouth mask can be attached the nebulizer. The nebulizing equipment should be cleaned immediately after use to prevent clogging of small orifices by residues and corrosion of metal parts.


A total of 6 drugs, 42 generic and brand names are known to interact with acetylcysteine. One drug, which comprises of 3 generic and brand names has a moderate interaction with acetylcysteine.

This drug that interacts moderately with acetylcysteine should be avoided, and used in combination only in exceptional circumstances. The effects of combining acetylcysteine with this drug are somewhat clinically significant.

39 generic and brand names have minor interactions with acetylcysteine. For these medications with trivial interactions, the effects of combinations are minimally clinically significant. Assess the risks involved and seek alternatives. Otherwise, the two can be combined and a monitoring plan instituted.

The following drugs should always be checked for when used in combination with acetylcysteine.

  • Aspirin low strength (Aspirin)
  • Calcium 600 D (Calcium / Vitamin D)
  • CoQ10 (Ubiquinone)
  • Fish oil (Omega 3 polyunsaturated fatty acids)
  • Gingko Biloba (gingko)
  • L-Carnitine (Levocarnitine)
  • Lipitor (atorvastatin)
  • Nexium (esomeprazole)
  • Probiotic formula (bifidobacterium infantis/ lactobacillus acidophilus)
  • Singulair (montelucast)
  • Spiriva (tiotropium)
  • Symbicort (budesonide/formoterol)
  • Tylenol (acetaminophen)
  • Vitamin B complex 100 (Multivitamin)
  • Vitamin B12 (cynocobalamin)
  • Vitamin B6 (pyridoxine)
  • Vitamin C (Ascorbic acid)
  • Zyrtec (Cetirizine)

Acetylcysteine may react with certain foods and tobacco. A doctor's advice should be sought on what to use that may improve the experience with the medicine and what to avoid. Tobacco may be contraindicated with this medicine as it also affects the lungs.


After correct administration of acetylcysteine, the volume of liquefied bronchial secretions may increase. When this happens, and the patient has a weak cough and therefore is not able to get rid of the excess mucus, institute removal by suction.

In case there is a foreign object or accumulation of mucus that is blocking the airway, endotracheal aspiration without or with bronchoscopy should be done.

Carefully monitor people with asthma taking acetylcysteine. Patients who experience bronchospasm should be carefully relieved by the use of a bronchodilator administered by nebulization. If the bronchodilator does not reduce the bronchospasm, acetylcysteine should be discontinued immediately.

If using this medicine in any way worsens symptoms, use should be discontinued, and medical advice sought.


Acetylcysteine should be stored in the refrigerator, but should not be frozen. An opened vial of the medicine should be used within four days. Discard what is still in the vial after four days.

The drug should be kept where children cannot reach. Medication that can no longer be used should not be stored but should be discarded immediately.


Acetylcysteine should be used as advised by a doctor to reduce the incidence of undesirable side effects. When used at home, a doctor's advice must be sought on how to use it. Loosened mucous must not be allowed to build up in the lungs.

Acetylcysteine is safe to use with children. No studies have indicated that it should produce different and undesirable side effects when used in pediatric cases. However, there has been no conclusive studies comparing the use of acetylcysteine with geriatric cases and other age groups.

The safe use of acetylcysteine for breastfeeding mothers has also not been established. Care should be taken when giving the drug to women who are breastfeeding. The risks of should be weighed against the benefits.

Besides, for more safety when using acetylcysteine, a doctor should be informed of any allergies that the patient may have. If the patient has previously had an allergic reaction to the drug, it is imperative to notify the doctor.

The doctor or health care professional should be informed of any other allergies the patient may have, such as to food, preservatives, dyes, or any other medicine.

If proper caution is observed, this medicine will be safe to use and will relive the patient's congestion in the lungs. It is highly rated by WHO and should be used without fear.

Last Reviewed:
December 10, 2017
Last Updated:
April 04, 2018