Medically reviewed by Drugs.com. Last updated on May 6, 2022.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Acetaminophen Antidote
Chemical Class: Amino Acid
Uses for acetylcysteine
Acetylcysteine is used to help prevent or lessen liver damage caused by an overdose of acetaminophen.
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.
Appropriate studies on the relationship of age to the effects of acetylcysteine have not been performed in the pediatric population. However, no pediatric-specific problems have been documented to date.
Although appropriate studies on the relationship of age to the effects of acetylcysteine have not been performed in the geriatric population, no geriatric-specific problems have been documented to date. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving acetylcysteine.
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 receiving 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:
- Bleeding in the esophagus or
- Stomach ulcers, or history of—May increase risk for more serious side effects.
- Congestive heart failure or
- Hypertension (high blood pressure) or
- Kidney disease—Acetylcysteine contains sodium, which can make these conditions worse.
Proper use of acetylcysteine
Acetylcysteine will be given to you by a nurse or other healthcare professional while you are in the hospital. It works best when it is given as close to the time of overdose as possible. The more time that goes by after the overdose, the less effective the medicine will be in protecting your liver.
Acetylcysteine comes with a patient information leaflet. Read and follow the instructions carefully. Ask your doctor if you have any questions.
The effervescent tablets should be dissolved in water before taking. Follow the instructions provided by your doctor. The mixed solution should be taken within 2 hours.
There is usually a total of 17 doses of acetylcysteine, taken about 4 hours apart. If you vomit within 1 hour after you take your medicine, you will need to take another dose to make up for it.
Precautions while using acetylcysteine
Your doctor will check your progress closely while you are receiving acetylcysteine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to receive it. Blood and urine tests may be needed to check for unwanted effects.
Serious allergic reactions may occur after receiving acetylcysteine. Tell your doctor right away if you have difficulty with breathing or swallowing, fever, hives, itching skin, rash, nausea, reddening of the skin, especially around the ears, swelling of the eyes, face, or inside of the nose, or unusual tiredness or weakness.
Acetylcysteine may increase risk of bleeding in your esophagus and stomach. Tell your doctor if you have severe or ongoing vomiting after taking acetylcysteine.
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 or nurse immediately if any of the following side effects occur:
Incidence not known
- Difficulty with breathing or swallowing
- hives or itching
- rash with or without a fever
- reddening of the skin, especially around the ears
- severe or ongoing vomiting
- swelling of the eyes, face, or inside of the nose
- unusual tiredness or weakness
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:
- Mild nausea
- stomach upset
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
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Reviews (26)
- Compare alternatives
- Pricing & coupons
- Drug class: antidotes
- Drug Information
- Acetylcysteine inhalation
- Acetylcysteine Inhalation, oral/nebulization (Advanced Reading)
- Acetylcysteine Intravenous (Advanced Reading)
- Acetylcysteine Effervescent Tablets
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.