Anesthesiology
-
Preclinical and clinical evidence indicates that locally administered opioid agonists produce an antihyperalgesic effect through peripheral opioid receptors in inflamed tissue. Loperamide, a mu opioid agonist, does not cross the blood-brain barrier and therefore lacks central effects after systemic administration. The authors defined the effects of topical loperamide on a thermal injury-induced hyperalgesia. ⋯ Loperamide, a peripherally acting mu opioid agonist, applied topically at the site of inflammation possesses a significant antihyperalgesic action without any systemic side effects.