Epidemiology and pharmacoeconomic implications of non-steroidal anti-inflammatory drug-associated gastrointestinal toxicity

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely prescribed and used, especially to treat patients with osteoarthritis and rheumatoid arthritis. Since their introduction as a therapeutic class, a large body of literature has accumulated on the side-effects of these drugs. NSAIDs, through their inhibition of prostaglandin synthesis, can affect the renal and cardiovascular systems. However, the majority of reported side-effects are related to the gastrointestinal (GI) system, and the occurrence of these GI events adds significantly to the disease burden. Several factors have been identified that contribute to the risk of an NSAID-associated GI event. However, when considering risk, especially in clinical trials or observational studies, it is necessary to distinguish between baseline risk and NSAID-attributable risk, since this distinction can affect the results and conclusions of the study; NSAID-attributable risk is present in subjects who have few or no risk factors for upper GI toxicity. Safer NSAIDs, such as the new specific cyclooxygenase-2 inhibitors, when targeted to the appropriate patient (i.e. those with NSAID-attributable risk), should lead to improved outcomes and reduced costs.