What is the maximum daily dose of acetaminophen for adults?

• A. 3,000 mg per day
• B. 4,000 mg per day
• C. 5,000 mg per day
• D. 2,000 mg per day

Answer: (B)

Acetaminophen has a daily safety ceiling to prevent liver injury from a toxic metabolite that forms when the drug is used in excess. For healthy adults, the commonly accepted maximum is 4,000 mg in 24 hours. Keeping total intake at or below this amount allows the body’s normal metabolic pathways to safely process the drug without a buildup of the harmful metabolite, which can deplete the liver’s protective glutathione stores and cause hepatotoxicity.

Sometimes lower limits (around 3,000 mg) are advised for people with liver disease, chronic alcohol use, or other risk factors, but the general maximum for adults without those risks is 4,000 mg daily. Taking 5,000 mg or more greatly increases the risk of severe liver injury, while 2,000 mg is well below the recommended ceiling and may not provide adequate pain relief when higher dosing is appropriate.