Combination systemic therapies in psoriatic arthritis.

Psoriatic arthritis (PsA) is a chronic, progressive, and debilitating disorder. When monotherapy fails, combination therapy is necessary for the long-term management of these patients. There is currently no review on this subject, and the purpose of this study was to investigate and describe the current literature on combination therapy in PsA. A PubMed MeSH search was performed for psoriatic arthritis and combination therapy, which yielded at total of 83 articles. After excluding reviews and commentaries, and pursuing relevant citations, a total of 21 articles on the subject were found: one study of NSAIDs and methotrexate, three studies of cyclosporine and methotrexate, three studies of non-TNF biologic inhibitors (alefacept, ustekinumab) and methotrexate, and 14 studies of anti-TNF-inhibitors (etanercept, adalimumab, infliximab, golimumab) and methotrexate. The combination of cyclosporine and methotrexate reduces the dosages and also the side effects of each agent, allowing better disease control with less toxicity. Methotrexate in combination with biologic agents, either non-TNF inhibitors or anti-TNF inhibitors, may have a role in decreasing side effects, but it does not appear to improve clinical symptoms beyond those attained by biologic monotherapy.