Topical NSAID Formulations

OBJECTIVE: This article reviews topical nonsteroidal anti-inflammatory drug (NSAID) formulations available in the United States, including advantages and disadvantages, therapeutic usefulness, adverse effects, and formulation considerations. RESULTS: In the United States, several topical NSAID products are approved to treat painful conditions including diclofenac sodium 1% gel (Voltaren Gel®; Endo Pharmaceuticals), diclofenac sodium topical solution 1.5% w/w in 45.5% dimethyl sulfoxide (PENNSAID®; Mallinckrodt, Inc.), and diclofenac epolamine 1.3% (Flector Patch®; Alpharma Pharmaceuticals LLC, a subsidiary of Pfizer, Inc.). Recent studies suggest topical diclofenac preparations are effective for osteoarthritis pain and suggest the efficacy of topical formulations is similar to that achieved with oral NSAID formulations. All NSAID formulations contain the same boxed warnings regarding cardiovascular and renal toxicity; however, topical NSAIDs are proposed to have a more favorable safety profile than oral NSAIDs due to the low serum concentrations achieved with topical NSAID formulations. CONCLUSIONS: Topical NSAIDs have been shown to be beneficial from both a therapeutics and adverse effect perspective, and are increasingly recommended in treatment guidelines.