Medically reviewed by Drugs.com. Last updated on Oct 23, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Diagnostic Agent, Bronchial
Chemical Class: Amino Acid
Uses for acetylcysteine
Acetylcysteine is a mucolytic (medicine that destroys or dissolves mucus). It is usually given by inhalation but may be given in other ways in a hospital.
Acetylcysteine is used for certain lung conditions when increased amounts of mucus make breathing difficult. Acetylcysteine liquefies (thins) or dissolves mucus so that it may be coughed up. Sometimes the mucus may have to be removed by suction.
Acetylcysteine is available only with your doctor's prescription.
Before using acetylcysteine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For acetylcysteine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to acetylcysteine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Although there is no specific information comparing use of acetylcysteine in children with use in other age groups, acetylcysteine is not expected to cause different side effects or problems in children than it does in adults.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of acetylcysteine in the elderly with use in other age groups.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking acetylcysteine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using acetylcysteine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of acetylcysteine. Make sure you tell your doctor if you have any other medical problems, especially:
- Asthma—Acetylcysteine may make the condition worse
- Decreased ability to cough—The mucus may have to be removed by suctioning
Proper use of acetylcysteine
Use acetylcysteine only as directed. Do not use more of it and do not use it more often than your doctor ordered. To do so may increase the chance of side effects.
If you are using acetylcysteine at home, make sure you understand exactly how to use it. If you have any questions about this, check with your doctor.
After using acetylcysteine, try to cough up the loosened or thinned mucus. If this does not work, it may have to be suctioned out. This will prevent too much mucus from building up in the lungs. If you have any questions about this, check with your doctor.
The dose of acetylcysteine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of acetylcysteine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For inhalation dosage form (solution):
- To thin or dissolve mucus in lung diseases:
- Adults and children—
- 3 to 5 milliliters (mL) of a 20% solution or 6 to 10 mL of a 10% solution used in a nebulizer three or four times a day. The medicine is inhaled through a face mask, mouthpiece, or tracheostomy.
- The 10 or 20% solution may be used for inhalation as a heavy mist in a tent or croupette.
- Sometimes the 10 or 20% solution is placed directly into the trachea or through a catheter into the trachea for certain conditions.
- Adults and children—
- For use in tests to diagnose lung problems:
- Adults and children—1 to 2 mL of a 20% solution or 2 to 4 mL of a 10% solution used for inhalation or placed directly into the trachea two or three times before the test.
- To thin or dissolve mucus in lung diseases:
If you miss a dose of acetylcysteine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store in the refrigerator. Do not freeze.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Store unopened vials of acetylcysteine in the refrigerator. Do not freeze. An open vial of medicine must be used right away.
The opened container should be discarded after 4 days.
Precautions while using acetylcysteine
If your condition does not improve or if it becomes worse, check with your doctor.
Acetylcysteine side effects
Along with its needed effects, a medicine 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 as soon as possible if any of the following side effects occur:
- Wheezing, tightness in chest, or difficulty in breathing (especially in asthma patients)
- Skin rash or other irritation
Some side effects 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:
- 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.
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about acetylcysteine
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Interactions
- Compare Alternatives
- Pricing & Coupons
- 21 Reviews
- Drug class: antidotes
- Drug Information
- Acetylcysteine inhalation
- Acetylcysteine (Advanced Reading)
- Acetylcysteine Intravenous (Advanced Reading)
- Acetylcysteine Effervescent Tablets
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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.