Purpose: Published reports on placebo-controlled clinical trials and other studies investigating the use of pure opioid antagonists for the prevention and treatment of opioid-induced pruritus (OIP) were evaluated.
Summary: OIP is a common adverse effect of therapeutic use of opioid medications that can have a major impact on patients' comfort, quality of life, and willingness to continue opioid therapy. A literature search identified more than a dozen published reports on the use of pure opioid antagonists (naloxone, naltrexone, methylnaltrexone) for the management of OIP in pediatric and adult patients. Of the studies included in this review, most investigated the effects of naloxone administered by various parenteral routes for the prevention of OIP. Some of those studies indicated a significant reduction in the frequency or severity of pruritus with use of naloxone (a low-dose, continuous i.v. infusion of naloxone appeared to be the most effective treatment). A significant diminution of analgesia requiring increased cumulative doses of morphine was also observed in some studies. A number of studies evaluating the use of orally administered naltrexone for the management of OIP yielded generally less favorable results. Evidence from one small study suggested a potential role for orally administered methylnaltrexone in the prevention of OIP.
Conclusion: Based on the existing data, a low-dose, continuous i.v. infusion of naloxone has the largest body of evidence supporting its use for prevention of OIP in adult and pediatric patients.