In adult patients presenting to the emergency department with acute pain, a single dose of ibuprofen 400 mg provides equal analgesic effect compared with 600 or 800 mg after 60 min.

In the emergency department there has been uncertainty over the analgesic ceiling for ibuprofen in the treatment of mild to moderate acute pain. A recent randomised trial addressed the minimally effective dose used to optimise pain management. Clinicians may reduce the rate of adverse events by using the minimally effective dose both in the emergency department and for discharge prescriptions.

In this double-blind, randomised controlled trial of 225 adults, Motov et al compared three single-dose regimens of 400, 600 and 800mg of oral ibuprofen to treat acute pain in the emergency department. Patients with peptic ulcer disease, gastrointestinal haemorrhage, renal or hepatic insufficiency, allergy to NSAIDS, altered mental status, those who were pregnant or breast feeding and those who had received opioids or NSAIDs in the previous 4hours, were excluded. Pain scores were recorded on a scale of 0–10 at baseline and at 60min.
At baseline, there was no difference in mean pain score between the 400, 600 and 800mg groups. There was no dose- dependent analgesic effect observed: after 60min, all dosages reduced pain scores by the same degree. No adverse events were recorded.
Several methodological strengths make the results likely to be valid. These include computer randomisation, blinded physicians, nurses, patients and outcome assessors, indistinguishable oral suspensions of each dosage, low attrition rate, intention-to-treat analysis and adequate power for the primary outcome.

This study establishes 400mg as a minimally effective single dose, and the evidence shows that short term use of ibuprofen is safe at a maximum dose of 1200mg; however, the risk of adverse effects rises sharply beyond 1200mg. While the subject study was underpowered to assess adverse events, ibuprofen given at doses greater than or equal to 1800 mg/day has been shown to double the odds of gastrointestinal complications from an OR of 1.9–3.9 when compared with daily doses of 1200 mg or less.