Acetylcysteine | Side Effects, Dosage, Uses & More
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Generic Name:

acetylcysteine, Inhalation solution

All Brands

  • Mucomyst (Discontinued)
A discontinued drug is a drug that has been taken off the market due to safety issues, shortage of raw materials, or low market demand.
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Highlights for acetylcysteine

Inhalation solution
1

Acetylcysteine is used to help break up thick, sticky mucous that can form in your airway if you have certain diseases. These diseases include bronchitis, pneumonia, emphysema, asthma, cystic fibrosis, and tuberculosis.

2

This drug is a solution that you inhale. You need to use a machine that turns this drug into a mist (nebulizer). You inhale the mist to take this drug.

3

This drug is only available as a generic drug.

4

More common side effects of taking this drug include sore or swollen mouth, nausea, vomiting, fever, drowsiness, and a runny nose.

IMPORTANT INFORMATION

People with asthma

Make sure someone is with you when you take acetylcysteine if you have asthma. You may be at increased risk of wheezing, tightness in your chest, and difficulty breathing (bronchospasm) after inhaling this drug.

Drug features

Acetylcysteine is a prescription drug. It comes in a solution you inhale. It’s only available as a generic drug.

It can be used as part of a combination therapy. This means you may need to take it with other medications.

Why it's used

Acetylcysteine is used to help break up the thick, sticky mucous that can form in your airway if you have certain diseases. These diseases include bronchitis, pneumonia, emphysema, asthma, cystic fibrosis, and tuberculosis.

How it works

Acetylcysteine belongs to a class of drugs called mucolytics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

More Details

How it works

Acetylcysteine belongs to a class of drugs called mucolytics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Acetylcysteine reacts with the chemicals in mucous to make it less sticky and easier to cough up. This will clear your airways and make it easier for you to breathe.

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acetylcysteine Side Effects

Inhalation solution

More Common Side Effects

Some of the more common side effects that can occur with use of acetylcysteine include:

  • stomatitis

  • nausea

  • vomiting

  • fever

  • rhinorrhea

  • drowsiness

  • claimminess

  • chest tightness

  • wheezing

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Bronchospasm. Symptoms can include:

    • wheezing
    • tightness in chest
    • difficulty breathing
Pharmacist's Advice
Healthline Pharmacist Editorial Team

As acetylcysteine breaks up the thick, sticky mucous, you will begin to cough more often to get rid of the mucous.

This drug will not make you tired.

Make sure someone is with you when you take acetylcysteine if you have asthma. You may be at increased risk of wheezing, tightness in your chest, and difficulty breathing (bronchospasm) after inhaling this drug.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
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acetylcysteine May Interact with Other Medications

Inhalation solution

Acetylcysteine may interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Don’t mix acetylcysteine with other drugs in a nebulizer. This use hasn’t been studied.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Acetylcysteine warnings
asthma
People with asthma

You may be at increased risk of wheezing, tightness in your chest, and difficulty breathing (bronchospasm) after inhaling this drug if you have asthma. Make sure someone is with you when you take acetylcysteine.

pregnant women
Pregnant women

Acetylcysteine is a category B pregnancy drug. That means two things:

  1. Studies of the drug in pregnant animals have not shown a risk to the fetus.
  2. There aren’t enough studies done in pregnant women to show if the drug poses a risk to the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the fetus.

breastfeeding
Women who are breast-feeding

Acetylcysteine may pass into breast milk. This may cause side effects in a child who is breastfed.

Talk to your doctor if you breastfeed your baby. You may need to decide whether to stop breastfeeding or stop taking this drug.

allergies
Allergies

Acetylcysteine can cause a severe allergic reaction. Symptoms can include:

  • trouble breathing
  • swelling of your throat or tongue

Call 9-1-1 or go to the nearest emergency room if you develop these symptoms.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal.

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How to Take acetylcysteine (Dosage)

Inhalation solution

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Break up mucous in your airway

Brand: Acetylcysteine

Form: Inhaled solution
Strengths: 10% (100 mg/mL) or 20% (200 mg/mL) solution
Adult dosage (ages 18 years and older)
  • Nebulized into a face mask, mouth piece, or tracheostomy: The recommended dose for most patients is 3–5 mL of the 20% solution or 6–10 mL of the 10% solution, three to four times per day. However, doses can range from 1–10 mL of the 20% solution or 2–20 mL of the 10% solution. These doses may be given every 2–6 hours.
  • Nebulized into a tent: You will need to use enough acetylcysteine (10% or 20%) to maintain a heavy mist in the tent for the length of time your doctor prescribes. You may use as much as 300 mL of acetylcysteine during a single treatment.
Child dosage (ages 0–17 years)
  • Nebulized into a face mask, mouth piece, or tracheostomy: The recommended dose for most patients is 3–5 mL of the 20% solution or 6–10 mL of the 10% solution, three to four times per day. However, doses can range from 1–10 mL of the 20% solution or 2–20 mL of the 10% solution. These doses may be given every 2–6 hours.
  • Nebulized into a tent: You will need to use enough acetylcysteine (10% or 20%) to maintain a heavy mist in the tent for the length of time your doctor prescribes. You may use as much as 300 mL of acetylcysteine during a single treatment.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

If you stop taking the drug or don’t take it at all

Symptoms such as wheezing and trouble breathing may get worse if you stop taking this drug or don’t take it at all.

If you miss doses or don’t take the drug on schedule

Symptoms such as wheezing and trouble breathing may get worse if you don’t take this drug as directed by your doctor. Talk to your doctor if you think it isn’t working as well for you anymore. Don’t change how often you take it without talking with your doctor.

If you take too much

Since you are inhaling acetylcysteine, it acts mainly in your lungs and an overdose isn’t likely. If you find that this drug isn’t working as well for you anymore and you’re using it more frequently than usual, call your doctor.

What to do if you miss a dose

Take your dose as soon as you remember. If you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once.

How to tell if the drug is working

You will cough up more mucus. Symptoms such as wheezing and trouble breathing should get better.

Acetylcysteine can be used as short-term or long-term treatment.

The length of therapy will depend on your condition.

Important considerations for taking this drug

Store unopened acetylcysteine vials at room temperature

Keep them from 68°F to 77°F (20°C to 25°C). Keep them away from high temperatures.

If you use only some of the solution in a vial, store the rest in a refrigerator. Use it within 4 days.

If you need to dilute your dose, use it within 1 hour. The solution may change color after your open the vial. This won’t change how well the drug will work.

A prescription for this medication is refillable

You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport x-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

You need to use a nebulizer. A nebulizer is a machine that turns the drug into a mist that you inhale. Not all nebulizers will work the same. Your doctor will tell you which type to use and show you how to use it.

These are the basic steps to set up and use your nebulizer:

  • Connect the hose to an air compressor.
  • Fill the medicine cup with your dose. To avoid spills, close the medicine cup tightly and always hold the mouthpiece straight up and down.
  • Attach the hose and mouthpiece to the medicine cup.
  • Place the mouthpiece in your mouth. Keep your lips firm around the mouthpiece so that all of the medicine goes into your lungs.
  • Breathe through your mouth until all the medicine is used. This can take 10–15 minutes or more. If needed, use a nose clip so that you breathe only through your mouth. Small children usually do better if they wear a mask.
  • Turn off the machine when done.

Wash the medicine cup and mouthpiece with water and air dry until your next treatment. It is important to take the time to keep your nebulizer clean so that it works properly.

Your doctor may have you check your lung function. Your doctor may ask you to record your symptoms or to check how well your lungs are working. You will do this with a peak flow meter.

Clinical monitoring

Your doctor will check your lung function. Your doctor will monitor your lung function with pulmonary function tests. These are breathing tests.

Hidden costs

You need a nebulizer for use at home. A nebulizer is a machine that turns the liquid solution into a mist, which can then be inhaled. Most insurance companies will cover the cost of a nebulizer. Depending on your condition, you may need to buy a peak flow meter. You can buy a peak flow meter at your pharmacy.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

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How Much Does acetylcysteine Cost?

Inhalation solution

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Lowest price for acetylcysteine

Walmart $12.00
Kroger Pharmacy $16.34
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These prices represent the lowest priced national pharmacies for acetylcysteine on GoodRx. They may be lower than your insurance.

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These prices represent the lowest priced national pharmacies for acetylcysteine on GoodRx. They may be lower than your insurance.

Show Sources

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on October 21, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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