Efficacy and safety of oral naltrexone treatment for pruritus of cholestasis, a crossover, double blind, placebo-controlled study

Background/Aims: To assess the efficacy and safety of naltrexone for the short and long term treatment of pruritus of cholestasis. Methods: Twenty patients with pruritus and cholestasis were included. A baseline pruritus score was obtained over 1 week. Patients were then randomized to receive 50 mg/day of naltrexone or placebo for 2 weeks. Subsequently, a 1-week washout period ensued and patients were crossed over to the other therapy for 2 additional weeks. Pruritus was assessed daily with a visual analogue scale (VAS) from 0 to 10. Patients whose pruritus decreased >50% of basal with naltrexone received naltrexone 50 mg/day for 2 additional months. Results: Mean basal VAS was similar in both groups. VAS showed greater and more significant changes with naltrexone than with placebo (P<0.0003). In nine out of 20 patients (45%) receiving naltrexone, pruritus decreased >50% compared to basal value, including five whose pruritus disappeared completely. No significant changes were observed in serum biochemistry. Most of the adverse events that occurred during the first 48 h of naltrexone therapy were consistent with opioid withdrawal-like phenomena and spontaneously disappeared 2 days after starting treatment. Conclusions: Naltrexone can be considered as an alternative option to treat pruritus of cholestasis. In the current study, side effects were transient and did not require specific medication.