The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.
This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.
Oral naltrexone treatment for cholestatic pruritus: a double-blind, placebo-controlled study.
The efficacy of currently available therapeutic agents for cholestatic pruritus is often disappointing. The aim of this study was to assess the antipruritic effect of naltrexone, an oral opiate receptor antagonist.
                Sixteen patients with pruritus of chronic cholestasis were randomized to receive naltrexone (4-week course of 50 mg naltrexone daily) or placebo. Pruritus, quality of sleep, fatigue (using visual analogue scales), side effects, and liver function were assessed every 2 weeks. Serum naltrexone and 6 beta-naltrexol concentrations in all patients and 5 healthy controls were measured during the first day of naltrexone treatment.
                Mean changes with respect to baseline were significantly different, in favor of the naltrexone group, for daytime itching (-54% vs. 8%; P < 0.001) and nighttime itching (-44% vs. 7%, P = 0.003). In 4 naltrexone-treated patients, side effects (transient in 3 cases) consistent with an opiate withdrawal syndrome were noted. No deterioration of the underlying disease was observed. Naltrexone and 6 beta-naltrexol levels did not differ between patients and controls, and there was no significant association with treatment response.
                For patients with cholestatic liver disease and itching, refractory to regular antipruritic therapy, oral naltrexone may be an effective and well-tolerated alternative.