Nonsteroidal anti-inflammatory agents in neonates.

The use of NSAIDs has become routine for adults and children in the management of pain. NSAIDs (other than aspirin [acetylsalicylic acid]) are also enjoying greater popularity as antipyretics since the recognition of Reye's syndrome's putative association with aspirin. In neonates, NSAIDs have been used for many years in an attempt to pharmacologically close the ductus arteriosus. This review examines the various NSAIDs and their potential and real applications in the neonatal population. For completeness, acetaminophen (paracetamol), which has weak NSAID activity and is a widely used analgesic and antipyretic in this patient group, was also included. The prostaglandin system is important for healthy development, and conversely there are unique risks posed by pharmacologic interference with this system in the neonatal period. The prostanoid system in neonates has the capacity to modulate nociception, but comes at the expense of interfering with nearly every organ system. Physiologic effects of inhibition of prostaglandin synthesis applicable to neonates include disruption of the sleep cycle, increased risk of pulmonary hypertension, alterations in cerebral blood flow, decreased renal function, disrupted thermoregulation, and alterations in hemostasis balance, among others. Prostaglandins are also important for the normal development of the central nervous, cardiovascular, and renal systems, and there is evidence that the proper genesis of these systems may be adversely effected by NSAID exposure in utero and in the neonatal period. Gastrointestinal adverse effects have provided the impetus for the development and marketing of selective cyclo-oxygenase type 2 (COX-2) inhibitors. These agents' reputation for safety in adults may not be applicable to neonates. COX-2 is involved in the development of several organ systems, and its inhibition may induce a prothrombotic state. The advent of parenteral formulations of cyclo-oxygenase inhibitors, including COX-2-selective agents, increases the therapeutic flexibility of NSAIDs. However, objective data on the safety of these agents have not kept pace with their clinical availability.