What is the max dose of acetaminophen?

• A. 3 g/day
• B. 4 g/day
• C. 5 g/day
• D. 6 g/day

Answer: (C)

Acetaminophen dosing is about staying within a safe limit to protect the liver. The liver detoxifies the drug, but at high amounts the toxic metabolite NAPQI can accumulate and cause liver injury. To prevent that, adults are generally advised not to exceed 4,000 mg (4 g) in 24 hours, with no more than 1,000 mg per single dose. In people with liver disease, chronic alcohol use, malnutrition, or those taking multiple acetaminophen-containing products, a lower limit (often around 3,000 mg per day or less) is recommended.

From the choices given, the safe upper daily limit is 4 g/day. A dose of 5 g/day would exceed the typical safe ceiling and increase the risk of severe liver injury, while 3 g/day can be acceptable in some situations but is lower than the standard maximum. The 4 g/day limit is the guideline most clinicians use to balance pain relief with safety.