Non-pharmacological interventions are the first-line therapy for osteoarthritis. If non-pharmacological therapy fails, paracetamol (up to 4 g daily) should be added. If paracetamol fails, the patient's risk factors for gastrointestinal and renal disease should be assessed. In patients with gastrointestinal risk factors, a COX-2-specific inhibitor (CSI) would be used in preference to a conventional non-steroidal anti-inflammatory drug (NSAID). In patients with renal risk factors, NSAIDs and CSIs should be used with care. In patients who continue to have problems, other treatments should be considered; these might include intra-articular hyaluronan or depot corticosteroid, analgesia or glucosamine.