What is the recommended dose and route for acetaminophen in adults and children?

• A. 10 mg/kg IV every 4 hours
• B. 20 mg/kg PO once
• C. 5 mg/kg IM every 6 hours
• D. 15 mg/kg PO or PR to max 1000 mg

Answer: (D)

Dosing with acetaminophen is weight-based for children and follows a fixed per-dose maximum for everyone. The recommended approach is 15 mg per kilogram given by mouth or rectally, up to a maximum of 1000 mg per dose. This per-dose limit helps prevent liver toxicity.

In adults, the same per-dose cap applies, and a common practical plan is about 650–1000 mg every 4–6 hours as needed, not exceeding the 4 g per day limit. The key point is the per-dose ceiling of 1000 mg and the available routes by mouth or rectum.

The other options don’t align with standard practice: the intravenous dose and interval shown aren’t the usual regimen; a single 20 mg/kg dose exceeds the typical per-dose maximum for many patients; and giving an acetaminophen formulation intramuscularly is not a standard route for routine dosing.