Gastrointestinal effects of nonsteroidal anti-inflammatory therapy.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for the treatment of many conditions including rheumatoid arthritis, osteoarthritis, gouty arthritis, the joint and muscle discomfort associated with systemic lupus erythematosus, and other musculoskeletal disorders. Yet, their benefits, which are believed to be a result of their ability to inhibit cyclooxygenase-2 (COX-2), are accompanied by considerable toxicity. NSAIDs' untoward effects are attributed to their inhibition of the constitutively expressed enzyme cyclooxygenase-1 (COX-1), with attendant suppression of the synthesis of prostanoids, substances that mediate key homeostatic functions. Side effects include suppression of hemostasis through inhibition of platelet aggregation, adverse effects in patients with heart failure and cirrhosis, and those with certain renal diseases, as well as complicating antihypertensive therapies involving diuretics or beta-adrenoceptor blockade. Perhaps most importantly, NSAIDs disrupt the gastrointestinal mucosal-protective and acid-limiting properties of prostaglandins, frequently leading to upper gastrointestinal erosions and ulceration, with possible subsequent hemorrhage and perforation. These complications can be reduced through identification of patients at risk, with circumspect use of NSAIDs, careful functional monitoring, and, in the case of gastrointestinal toxicity, co-administration of such agents as misoprostol or omeprazole. However, these strategies introduce complexity into the treatment paradigm. Moreover, side effects and adverse events may be significantly reduced through the use of COX-2-specific inhibitors, new agents that alleviate pain and inflammation without the liability for adverse events caused by COX-1 inhibition.