A new meta-analysis has ranked topical NSAIDs in terms of their efficacy in osteoarthritis – but with the top slot going to a formulation that is not available in Australia

Topical diclofenac in patch form was found to be the most effective topical NSAID in the first network meta-analysis of randomised controlled trials (RCTs) and observational studies of the agents in osteoarthritis, published in the British Journal of Sport Medicine.

The authors of the review of 36 RCTs and seven observational studies in OA said it was the first to rank topical NSAIDs by their formulation and also expanded on the previous meta-analysis from 2009 that covered only 13 RCTs.

It found that topical diclofenac patch was the most effective topical NSAID for pain relief, followed by ibuprofen cream. Topical piroxicam was the most effective for functional improvement.

However the reviewers noted that most of the studies were of short to medium duration – typically 1-6 weeks, and none of the topical NSAIDs showed changes in outcomes above what was considered to be the minimal clinically important difference for (a 1.2cm decrease on a 10cm visual analogue scale).

And in contrast to smaller individual studies, the meta-analysis found no increase in risk of adverse events such as skin reactions or systemic effects such as GI problems with topical NSAIDs, with the exception of salicylate.

“On the basis of our findings, topical NSAIDs can be readily prescribed for the treatment of OA irrespective of common comorbidities or other medications,” they suggested.

The reviewers concluded that based on their findings, a topical diclofenac patch could be considered the first line topical NSAID. The superior efficacy of the patch formulation was a novel finding, they added.

“This may be due to the constant and continuous delivery of the active ingredient to the affected area by means of an occlusive bandage and slow release of the drug when compared with traditional topical formulations such as gel and solution,” they said.

The study, a joint venture between rheumatologists at universities in China and Nottingham University, UK, was government funded and had no declared conflicts of interest.

Topical NSAIDs ranked in terms of pain relief vs placebo:

1. Diclofenac patch
2. Ibuprofen
3. Piroxicam
4. Nimesulide
5. Diclofenac gel
6. Ketoprofen
7. Salicylate
8. Etorocoxib