Nonsteroidal anti-inflammatory drugs (NSAIDs), including both traditional nonselective NSAIDs and the selective cyclooxygenase (COX)-2 inhibitors, are widely used for their anti-inflammatory and analgesic effects. NSAIDs are a necessary choice in pain management because of the integrated role of the COX pathway in the generation of inflammation and in the biochemical recognition of pain. This group of drugs has recently come under scrutiny because of recent focus in the literature on the various adverse effects that can occur when applying NSAIDs.This review will provide an educational update on the current evidence of the efficacy and adverse effects of NSAIDs. It aims to answer the following questions: (1) are there clinically important differences in the efficacy and safety between the different NSAIDs, (2) if there are differences, which are the ones that are more effective and associated with fewer adverse effects, and (3) which are the effective therapeutic approaches that could reduce the adverse effects of NSAIDs. Finally, an algorithm is proposed which delineates a general decision-making tree to select the most appropriate analgesic for an individual patient based on the evidence reviewed. Keywords: Analgesics; COX-2 specific inhibitors; NSAIDs; Pain Nonst eroidal anti-inflammatory drugs (NSAIDs) are among the most widely used medications in the world because of their demonstrated efficacy in reducing pain and inflammation. 1 Their efficacy has been documented in a number of clinical disorders, including osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, gout, dysmenorrhea, dental pain and headache. [2][3][4][5][6][7][8] The basic mode of action is inhibition of the pro-inflammatory enzyme cyclooxygenase (COX). NSAIDs as a class comprise both traditional nonselective NSAIDs (tNSAIDs) that nonspecifically inhibit both COX-1 and COX-2, and selective COX-2 inhibitors. Although effective at relieving pain and inflammation, tNSAIDs are associated with a significant risk of serious gastrointestinal adverse events with chronic use. 9 Therefore, specific inhibitors of the COX-2 isoenzyme were developed, thus opening the possibility to provide antiinflammatory and analgesic benefits, while theoretically leaving the gastroprotective activity of the COX-1 isoenzyme intact. However, important concerns have recently been raised regarding the potential cardiovascular toxicity of COX-2 inhibitors. 10This review will provide an educational update of the scientific evidence for the efficacy and adverse effects of NSAIDs in view of the emerging new information for this class of drugs. It is composed deliberately to be a classic, pragmatic review and draws on the results of published systematic reviews and studies regarding the topic. It aims to answer the following questions: (1) are there clinically important differences in the efficacy and safety between the different NSAIDs, (2) if there are differences, which are the ones that are more effective and associated with fewer adverse effects, and (3) which are...