Acetaminophen overdose antidote

Acetylcysteine, the 4 gram cap, and hidden sources.

Short answer

The antidote for acetaminophen (Tylenol) overdose is acetylcysteine (N-acetylcysteine, Mucomyst). Acetaminophen overdose damages the liver, so acetylcysteine is given to protect it, ideally early. The maximum daily dose for a healthy adult is about 4 grams, and hidden acetaminophen in combination products is a common cause of accidental overdose.

Why acetaminophen has an antidote, and why the NCLEX tests it

Acetaminophen is safe at normal doses but hepatotoxic in overdose, and it hides in many combination cold and pain products. The exam pairs the drug with its antidote and tests the daily limit and hidden-source teaching.

Key nursing considerations for the acetaminophen antidote

The antidote is acetylcysteine

Acetylcysteine (N-acetylcysteine, Mucomyst) protects the liver in acetaminophen overdose and works best given early.

The danger is the liver

Overdose causes hepatotoxicity that can progress to liver failure; monitor liver function.

Know the daily limit

About 4 grams per day for a healthy adult, lower (around 3 grams) with liver disease or regular alcohol use.

Watch hidden sources

Total up acetaminophen from all products, since many cold and combination pain medicines contain it.

Teach the cap

Teach patients not to exceed the daily limit and to check labels for acetaminophen.

How the NCLEX turns the acetaminophen antidote into a question

The exam reuses a few predictable angles. Learn to spot them and the question answers itself.

Report signs of liver injury or a known ingestion above the daily limit.

Priority total the acetaminophen from all sources and anticipate acetylcysteine for overdose.

Lab liver function tests, and the acetaminophen level to guide treatment.

Teach stay under about 4 grams a day, check other medicines so you do not double up on acetaminophen, and avoid alcohol.

NGN cue

A patient taking maximum Tylenol plus a combination cold medicine that also contains acetaminophen. Recognize the overdose risk from hidden sources.

Quick answers

What is the antidote for acetaminophen overdose?

Acetylcysteine (N-acetylcysteine, Mucomyst). It protects the liver and is most effective when given early.

What is the maximum daily dose of acetaminophen?

About 4 grams per day for a healthy adult, and lower (around 3 grams) for people with liver disease or regular alcohol use.

What organ does acetaminophen overdose damage?

The liver. Overdose causes hepatotoxicity that can progress to liver failure, so liver function is monitored.

Keep studying

These pages build on each other. Work through the related classes, then pressure-test yourself against the free cheat sheet and the full guide.


Cover of NCLEX-RN Pharmacology Made Manageable
Available now · instant download

Every high-yield class, decoded the same way

You just read the the acetaminophen antidote breakdown. The full guide runs all 54 high-yield drug classes on one repeatable system, then closes with the cram tables: antidotes, therapeutic drug levels, must-know lab values, the suffix sheet, and a final-week checklist.

Get the guide - $12.99 7-day money-back guarantee

98-page PDF + EPUB · instant download · 7-day money-back guarantee · free sample

Get the high-yield cheat sheet by email

Drop your email and we will send you the free High-Yield NCLEX Pharmacology Cheat Sheet as a printable PDF right away: antidotes, high-alert drugs, and the lab-value cutoffs the exam leans on. We email rarely, and you can unsubscribe in one click. Founding reviewers welcome: after you join, just reply to the welcome email and we will send you the full guide free to review honestly.