Analgesic agents for the postoperative period. Nonopioids.

For many reasons, nonopioid analgesics have proven to be of immense benefit in postoperative pain relief. Consideration of the limitations and side effects of opioids confirms the need for alternative, complementary analgesics. The current understanding of pain pathophysiology recognizes that many tissue and neuronal factors and changes are invoked by tissue damage, producing peripheral and central sensitization, and some of these may be modulated by the use of NSAIDs, NMDA antagonists, and local anesthetic agents. If successful preemptive analgesic techniques are developed, they will likely include the use of NSAIDs and perhaps NMDA antagonists. Nonopioids are of benefit in multimodal analgesia and allow acute rehabilitation of surgical patients. Acetaminophen, NSAIDs, alpha 2-antagonists, and NMDA antagonists are in routine use as components of multimodal analgesia, in combination with opioids or local anesthetic techniques. Tramadol is interesting because it has nonopioid and opioid actions that can be attributed to the two isomers found in the racemic mixture. Spinal neostigmine and the use of adenosine represent completely different mechanisms of nonopioid analgesia being investigated. Nonopioids, including lidocaine, ketamine, the anticonvulsants, and the antidepressants, are necessary for the treatment of patients with the difficult clinical problem of neuropathic pain that can present in the postoperative period.