Oral naltrexone therapy helps relieve cholestatic itch,suggests the findings of a recent study published in British Medical Journal ;further elaborating that although it should be used with caution in patients using exogenous opioids for analgesia, it can be considered when treating refractory pruritus in patients with end-stage liver disease.
Cholestatic itch is caused by intrahepatic liver diseases, such as primary biliary cirrhosis and extrahepatic obstruction of the biliary tree, often caused by tumours. The pathophysiology of cholestatic itch is complex and no single treatment has proved definitive. Recent studies show that endogenous opioids in the central nervous system have a role in creating the feeling of pruritus in these patients. Plasma levels of endogenouse opioids including enkephalin increase in patients with chronic cholestasis.
Naltrexone is an opioid receptor antagonist, which reduces central opioidergic tone, believed to be raised in patients with cholestatic pruritus.Previous research has shown that pruritus can be controlled by opioid antagonists such as naloxone. Injection of cholestatic patient's serum to monkey's medulla can cause pruritus that is controlled by naloxone. Several recent studies indicate that opioid antagonists such as naloxone and nalmefene are effective in reducing pruritus in patients with primary biliary cirrhosis.
With this background, the research team undertook the current study to review and assess the efficacy of oral naltrexone for the treatment of cholestatic itch.
This study design consisted of search of electronic databases, grey literature, clinical trials registries and handsearching for studies including naltrexone for cholestatic itch. Full papers were obtained if relevant and studies graded.
Data analysis revealed the following facts.
Thirteen papers were included in the analysis, including three randomised controlled trials, one controlled clinical trial, one open-label pilot study, seven case reports and one retrospective notes review.
All studies found naltrexone to be effective in relieving pruritus.
In all five studies performing statistical analysis, naltrexone significantly reduced pruritus compared with baseline. 37% of patients reported side effects, notably opioid withdrawal-type reactions and recurrence of previous pain, from all pathologies.
FOR FULL ARTICLE FOLLOW THE LINK: https://doi.org/10.1136/bmjspcare-2020-002801.
PRIMARY SOURCE: British Medical Journal