Adjuvant analgesics in acute pain.

INTRODUCTION: despite its central role in acute pain management, the exclusive use of opioids has been challenged recently in view of its immediate and long-term side effects. Development of chronic postsurgical pain syndromes, hyperalgesia and immunomodulation are some particular concerns as they may be related to opioid exposure, intertwined with patient characteristics and other factors. Application of a multimodal approach, administration of preventive analgesia and paradigm shift in surgical techniques all mandate a revisit of evidence-based perioperative pain management. AREAS COVERED: adjuvant analgesics are drugs indicated for primary non-pain conditions, but have been found efficacious in analgesia either when used alone or in combination with other analgesics. Among a diverse group of adjuvant analgesics, systemic administration of ketamine, magnesium, gabapentinoids, steroids, α2 agonists and lidocaine are reviewed, with recent evidence compared with earlier systematic reviews or meta-analyses from a Medline search (1990 - Apr 2010). EXPERT OPINION: for acute pain management, adjuvant analgesics in appropriate doses and monitored care are beneficial in improving analgesic efficacy and reduce opioid-related side effects with good safety and tolerability. However, the quest for an optimal regime for administration and individualizing treatment remains.