Answer
E: Topical diclofenac
Educational Objective
Treat osteoarthritis in an elderly patient using a topical NSAID.
Critique
Topical diclofenac is the most appropriate treatment for long-term symptom control for this elderly patient with knee osteoarthritis (OA). Acetaminophen has not provided relief; furthermore, the efficacy of acetaminophen for OA is increasingly being questioned because recent controlled trials and meta-analyses demonstrated no benefit from the drug, even at high doses. NSAIDs are available in oral, topical, and intravenous forms. Due to efficacy and cost-effectiveness, oral preparations are usually first-line NSAID therapy in patients without contraindications to treatment. In OA, topical NSAIDs are considered to provide similar pain relief as oral medications with fewer gastrointestinal effects. Furthermore, the American College of Rheumatology currently recommends topical NSAIDs rather than oral NSAIDs for patients aged 75 years or older. However, they are associated with more skin reactions and are significantly more expensive than oral NSAIDs. This elderly woman with unilateral knee OA is an ideal candidate for topical NSAIDs—she has just one area of musculoskeletal pain and has several relative contraindications to oral NSAIDs (age, chronic kidney disease, coronary artery disease, and aspirin intake).
When a single symptomatic joint is present, injection directly into the joint may deliver medication to the affected site while minimizing the potential for systemic effects. Intra-articular injections may be used along with or in place of oral or topical analgesics. Intra-articular glucocorticoids are associated with short-term benefit with few side effects. Glucocorticoid injection alone would not likely provide long-term benefit for this patient.
Low-dose oral prednisone is associated with modest reductions in short-term knee pain and may increase a 6-minute walk distance in older patients with moderate-to-severe knee OA. However, long-term use is associated with significant complications, including an increased risk for diabetes mellitus, osteoporosis, osteonecrosis, weight gain, fluid retention, hypertension, cardiovascular disease, striae and bruising, and glaucoma and cataracts.
Oral naproxen and other oral NSAIDs are relatively contraindicated given the patient's hypertension, chronic kidney disease, and coronary artery disease.
Traditional opiates may rarely be warranted to control pain in patients with OA who have not responded to other agents or are poor candidates for other interventions to treat painful joints, such as surgery. Opioid analgesics are inappropriate for this patient because other treatment options are available. In addition, opioids have limited effectiveness for chronic joint pain and are associated with substantial side effects in the elderly, especially increased fall risk, cognitive changes, and constipation.
Key Point
Topical NSAIDs are beneficial for patients at high risk for toxicity from oral NSAIDs.
Bibliogrpahy
Rannou F, Pelletier JP, Martel-Pelletier J. Efficacy and safety of topical NSAIDs in the management of osteoarthritis: Evidence from real-life setting trials and surveys. Semin Arthritis Rheum. 2016;45:S18-21. doi:10.1016/j.semarthrit.2015.11.007