Abstract
This review focuses on pharmacokinetics and pharmacodynamics of opioid and non-opioid analgesics in neonates and infants. The unique physiology of this population differs from that of adults and impacts drug handling. Morphine and remifentanil are described as examples of older versus recently developed opiates to compare and contrast pharmacokinetics and pharmacodynamics in infants. Exploration of genetics affecting both pharmacokinetics and pharmacodynamics of opiates is an area of active research, as is the investigation of a new class of mu-opiate-binding agents which seem selective for analgesic pathways while having less activity in pathways linked to side effects. The kinetics of acetaminophen and of ketorolac as examples of parenteral non-steroidal analgesics in infants are also discussed. The growth in regional anesthesia for peri-operative analgesia in infants can fill an important role minimizing intra-operative anesthetic exposure to opioids and transitioning to post-operative care. Use of multi-modal techniques is recommended to decrease undesirable opiate-related side effects in this vulnerable population.