Abstract: Seven studies were included, they were all parallel-group studies, two studies were assessed as at low risk of bias and three at high risk of bias; two were considered to have unclear bias in their methodology. A total of 2241 participants were enrolled in these trials. Ibuprofen was found to be a superior analgesic to paracetamol at several doses with high quality evidence suggesting that ibuprofen 400 mg is superior to 1000 mg paracetamol based on pain relief (estimated from TOTPAR data) and the use of rescue medication meta-analyses. The risk ratio for at least 50% pain relief (based on TOTPAR) at six hours was 1.47 (95% confidence interval (CI) 1.28 to 1.69; five trials) favouring 400 mg ibuprofen over 1000 mg paracetamol, and the risk ratio for not using rescue medication (also favouring ibuprofen) was 1.50 (95% CI 1.25 to 1.79; four trials). The combined drug showed promising results, with a risk ratio for at least 50% of the maximum pain relief over six hours of 1.77 (95% CI 1.32 to 2.39) (paracetamol 1000 mg and ibuprofen 400 mg) (one trial; moderate quality evidence), and risk ratio not using rescue medication 1.60 (95% CI 1.36 to 1.88) (two trials; moderate quality evidence). The information available regarding adverse events from the studies (including nausea, vomiting, headaches and dizziness) indicated that they were comparable between the treatment groups. However, we could not formally analyse the data as it was not possible to work out how many adverse events there were in total. There is high quality evidence that ibuprofen is superior to paracetamol at doses of 200 mg to 512 mg and 600 mg to 1000 mg respectively based on pain relief and use of rescue medication data collected at six hours postoperatively. The majority of this evidence (five out of six trials) compared ibuprofen 400 mg with paracetamol 1000 mg, these are the most frequently prescribed doses in clinical practice. The novel combination drug is showing encouraging results based on the outcomes from two trials when compared to the single drugs.

Plain-language summary: The evidence on which this review is based was current as of 20 May 2013. Seven studies with a total of 2241 participants all involving a direct comparison of ibuprofen to paracetamol or the combination of both were included in this review. All participants had surgery to remove a lower wisdom tooth or teeth that required bone removal or at least caused moderate to severe pain. Painkillers were taken after surgery and different doses of the drugs were compared. The majority of the studies took place in the USA with one in Puerto Rico. Four of the trials took place in clinical research facilities, two in university dental hospitals and one in a private oral surgery clinic. The age of participants differed slightly between studies but was broadly similar, ranging from 15 to 65 years old. All studies included male and female participants. All the studies included in this review looked only at pain relief and intensity information after a single dose of the painkiller after surgery. It is known that pain does continue after this and the drugs evaluated in this review are normally taken every six to eight hours (maximum of four times per day). Ibuprofen is more effective than paracetamol at all doses studied in this review. On limited evidence, the combination of ibuprofen and paracetamol appeared to be no more effective than the single drugs when measured two hours after surgery. However, again on limited evidence, it was found to be more effective than the drugs taken singly when measured at six hours after surgery. Participants taking the combined drug also had a smaller chance of requiring rescue medication. The information available regarding adverse events from the studies (including nausea, vomiting, headaches and dizziness) indicated that they were comparable between the treatment groups. However, review authors could not formally analyse the data as it was not possible to work out how many adverse events there were in total. All of the results (outcomes) comparing ibuprofen to paracetamol are of high quality. This means that further research is very unlikely to change our confidence in the estimates of the effect. When comparing combined versus single drugs, the body of evidence for the proportion of patients with > 50% maximum pain relief (TOTPAR) over two and six hours, was assessed as of moderate quality due to imprecise estimates based on single studies. This means that further research is likely to have an important impact on our confidence in the estimate of the effect. The body of evidence for the use of rescue medication was assessed as being of high quality.