The pharmacological treatment of osteoarthritis
The pharmacological treatment of Osteoarthritis (OA) has three goals: to relieve pain, to improve function and quality of life and to modify the course of the disease. Drugs targeting pain are analgesics, including opioid and non-opioid analgesics, oral or topical classical non-steroidal anti-inflammatory drugs, and selective cyclo-oxygenase-2 inhibitors (lumiracoxib, valdecoxib, etoricoxib, celecoxib). Chondroitin sulfate, glucosamine and diacerein showed efficacy in relieving pain and improving function in randomised trials, but meta-analyses showed conflicting results. Intra-articular corticosteroids and hyaluronans gave a variable relief from pain. The effect of medications on structural damage and course of the disease is questionable. Doxycycline, diacerein, chondroitin sulfate and glucozamine showed a beneficial effect on disease progression in randomised controlled trials (RCTs), but this effect is not invariably shown in meta-analyses. Cardiovascular safety concerns for NSAIDs have led to development of a cyclo-oxygenase-inhibiting, nitric oxide donator drugs (naproxcinod) that improved symptoms of OA, without adversely affecting blood pressure in RCTs. A dual cyclo-oxygenase and 5-lipoxygenase inhibitor (licofelone), that decreases the production of pro-inflammatory prostaglandins and leukotrienes showed a symptomatic and chondroprotective effect, along with a favorable gastrointestinal safety profile. Disease-modifying antirheumatic drugs for rheumatoid arthritis are being studied in OA. These include methotrexate, hydroxychloroquine, and drugs targeting cytokines, such as interleukin-1 (anakinra, canakinumab) and tumor necrosis factor-α (infliximab, adalimumab). Biphosphonates, drugs that suppress osteoclasts and bone turnover, (risendronate and clodronate) showed contradictory effects on symptoms and radiographic progression in OA, while a bradykinin-receptor antagonist, icatibant, did not show any clear effect on pain. A novel, oral inhibitor of type-4 phosphodiesterase, apremilast, that has anti-inflammatory effects through downregulation of tumor necrosis factor-α, is being investigated in OA. Botulinum toxin type A is also under study as a pain relief medication for OA. © 2012 by Nova Science Publishers, Inc. All rights reserved.