The role of analgesics in the management of osteoarthritis pain.

Osteoarthritis (OA), previously called degenerative joint disease, is a common condition. Figures from the United States indicate that as many as 80% of the population has radiographic evidence of this disease by the age of 65 years, and difficulty with ambulation, mostly attributable to OA, accounts for as many as 30% of all visits to a doctor. There is no known cure for OA and hence treatments are used to reduce pain and other symptoms, maintain and/or improve joint mobility, and limit functional disability, with the overall management goal of improving the patients' quality of life. To this point, one of the key objectives of treatment is to manage knee pain. In the past, treatment was most often initiated with the prescription of nonsteroidal anti-inflammatory drugs (NSAIDs). However, evidence that (1) NSAIDs offer no additional symptomatic benefit over simple analgesics, such as paracetamol (acetaminophen), for many patients with OA, (2) NSAID-related adverse gastrointestinal (GI) effects are a significant cause or morbidity and mortality, and (3) NSAIDs could have a possible deleterious effect on articular cartilage metabolism, has led to a change in management strategy. Contemporary thinking is that nonpharmacologic measures should be tried first, with pharmacologic intervention used as an adjunct. Nonpharmacologic therapy includes such things as patient education, weight loss, physical therapy, occupational therapy, and exercise. Paracetamol, in doses of as high as 4000 mg/day, is the first-line drug of choice for the management of the pain of OA. If the patient does not respond to paracetamol, NSAIDs may be an appropriate alternative, provided they are not medically contraindicated. Because of their GI toxicity, it is suggested that NSAIDs be used in the lowest possible dose for the shortest possible time. In OA, the intensity of pain varies both during the day and night, enabling the use of NSAIDs with a short half-life on an as-needed basis. Strategies to reduce the risk of NSAID-related GI complications include prophylaxis with misoprostol. Current developments in the field of OA management are also discussed, including the emergence of drugs that specifically inhibit cyclooxygenase 2 (COX-2) and disease-modifying treatments.