A prescription reads: "Ibuprofen 800 mg — take 2 tablets every 8 hours." What is wrong with it?

Correct answer: A. The dose exceeds the maximum safe daily amount of ibuprofen

• A. CORRECT. Two 800 mg tablets is 1600 mg per dose, and three doses a day gives 4800 mg in 24 hours. The maximum prescription-strength daily dose of ibuprofen is 3200 mg, and the single maximum dose is 800 mg. This regimen delivers 50% more than the ceiling, materially raising the risk of gastrointestinal ulceration and bleeding, acute kidney injury, and hypertension. The correct instruction is ONE 800 mg tablet every 8 hours, which gives 2400 mg per day.
• B. The regimen is not standard and is unsafe. It exceeds the maximum daily dose by 1600 mg.
• C. Eight-hourly dosing is entirely appropriate for ibuprofen and matches its 2 to 4 hour half-life with sustained anti-inflammatory effect. The interval is not the problem.
• D. 800 mg is a perfectly standard prescription-strength ibuprofen tablet and is the usual dose for dental pain. The tablet strength is not the error — the quantity per dose is.

Note: Numbers to hold: ibuprofen maximum 3200 mg/day prescription (1200 mg/day over the counter), single dose maximum 800 mg. Acetaminophen maximum 4000 mg/day for healthy adults, and 3000 mg or less in hepatic impairment or regular alcohol use. Alternating ibuprofen 400–600 mg with acetaminophen 500–1000 mg outperforms opioids for post-operative dental pain.