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Acetylcysteine (oral, effervescent)

Generic Name: acetylcysteine (oral, effervescent) (a SEET il SIS teen)
Brand Name: Cetylev

Medically reviewed by on Sep 20, 2019 – Written by Cerner Multum

What is acetylcysteine?

Acetylcysteine is an acetaminophen antidote that helps your body preserve a substance that can help detoxify the liver.

Acetylcysteine is used to treat acetaminophen overdose and help prevent damage to your liver caused by taking large quantities of acetaminophen (Tylenol).

There are other brands and forms of acetylcysteine available, and some can be purchased over the counter. Not all forms of acetylcysteine are effective as an acetaminophen antidote. Treatment of acetaminophen overdose should be managed by a medical doctor.

Acetylcysteine may also be used for purposes not listed in this medication guide.

Important Information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use acetylcysteine if you are allergic to it.

To make sure acetylcysteine is safe for you, tell your doctor if you have:

It is not known whether this medicine is harmful to use during pregnancy. However, an acetaminophen overdose may cause harm to both the mother and the baby. The benefit of treating the overdose may outweigh any risks of taking acetylcysteine. Tell your doctor if you are pregnant.

It is not known whether acetylcysteine passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

In an emergency situation it may not be possible to tell your caregivers if you are pregnant or breast-feeding. Make sure any doctor caring for your pregnancy or your baby knows you have received this medicine.

How should I take acetylcysteine?

Before you take acetylcysteine, your caregivers may perform a blood test to measure the level of acetaminophen in your body. This test is most effective when performed within 4 to 8 hours after you have taken acetaminophen. If you cannot remember when you last took acetaminophen, you will most likely be given the first dose of acetylcysteine right away.

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Do not swallow or chew an effervescent tablet. This tablet must be dissolved in water before you take it. Keep the tablet in its foil blister pack until you are ready to use it. Drop the tablet into a glass of water. Stir and drink this mixture right away.

Do not take acetylcysteine at home if you do not fully understand all instructions specific to your use of this medicine.

While using acetylcysteine, you may need frequent blood tests.

Your doctor will determine how long to treat you with acetylcysteine. Do not stop taking this medicine until your doctor tells you to.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking acetylcysteine?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Acetylcysteine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • severe or ongoing vomiting;

  • coughing up blood or vomit that looks like coffee grounds; or

  • signs that the medicine may not be working--upper stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect acetylcysteine?

Other drugs may interact with acetylcysteine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.