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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.





This medication, when inhaled by mouth, works in the lung to thin mucous, making breathing easier. It is used to treat thick mucous secretions in chronic emphysema, bronchitis, pneumonia, cystic fibrosis and other related conditions. This medication is also swallowed by mouth as an antidote to acetaminophen overdose in order to prevent life-threatening liver damage.



Acetylcysteine has also been swallowed by mouth to prevent kidney failure due to X-ray contrast products.

How To Use

When used to thin mucus, this medication is inhaled into the lungs using special breathing (nebulizer) equipment. A health care professional will demonstrate the proper way to use the equipment. Make sure you understand and ask any questions you may have. Use the solution as directed. Do not increase your dose or take this more frequently than directed. When swallowed by mouth for acetaminophen overdose or to prevent kidney problems, take exactly as directed. For acetaminophen overdose, this medication is generally used every 4 hours.

Side Effects

When using this to thin mucus, it may cause nausea, vomiting, drowsiness, runny nose, clamminess, fever and an unpleasant odor the first several days as your body adjusts to the medication. If any of these effects persist or worsen, inform your doctor promptly. Notify your doctor promptly if you develop: rash, mouth sores, breathing trouble. If using a face mask, your face may feel sticky after use. Wipe clean with water. When using this medication by mouth for acetaminophen overdose or to prevent kidney problems, it may cause or aggravate nausea and vomiting. Diluted solutions of this medication may minimize this problem. Consult the pharmacist for instructions on proper dilution of acetylcysteine. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor if you have any pre-existing conditions, such as: breathing disorders, digestive system problems (peptic ulcer disease, esophageal varices), any allergies. This drug may make you drowsy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages. This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. It is not known if this medication appears in breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of any prescription or nonprescription medication you may use. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately.


Do not share this medication with others.

Missed Dose

When using this to thin mucus: if you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up. When using this by mouth for acetaminophen overdose or prevention of kidney problems: immediately consult the doctor if any doses are missed.


Store unopened solution at room temperature between 59 and 86 degrees F (15 and 30 degrees C) away from heat and light. Once opened, store the solution in the refrigerator and use within 96 hours. The solution may change color, but will continue to be safe and effective if used within 96 hours after opening. Diluted solutions to be swallowed by mouth should be used within 1 hour of preparation.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).