Potential renal, haematological and allergic adverse effects associated with nonsteroidal anti-inflammatory drugs.

The major benefits of the perioperative administration of nonsteroidal anti-inflammatory drugs (NSAIDs) are related to the ability of these agents to provide analgesia without cardiovascular or respiratory depression. However, there are several possible adverse effects of NSAIDs. All NSAIDs reduce the synthesis of prostaglandins by the kidneys, but their administration in the perioperative period appears to have little potential for renal toxicity when adequate hydration is maintained and renal function is not dependent on renal prostaglandins. However, NSAIDs may cause impairment of renal function in patients with conditions such as hypovolaemia, congestive cardiac failure, or hepatic cirrhosis, since renal function in these patients may be dependent on the vascular effects of prostaglandins. Platelet aggregation is inhibited by the administration of NSAIDs, and most studies of their haematological effects report that NSAIDs are associated with an increase in bleeding times. In patients with normal haemostatic function before NSAID administration, almost all indices of coagulation remain within the normal range after NSAID treatment. Most studies of perioperative blood loss have reported no significant difference between the effects of NSAIDs and placebo in this regard. The incidence of major allergic reactions in the general population appears to be small with NSAIDs. Overall, NSAIDs appear to be safe and well tolerated drugs with a valuable role to play in the treatment of postoperative pain.