日本止痒药盐酸纳呋拉啡治疗透析患者瘙痒症的效果分析

Introduction: Nafurafine is an antipruritic drug marketed in Japan, used for pruritus in patients undergoing hemodialysis and chronic kidney disease. Clinical studies have shown that nalfurapine hydrochloride used three times a week can significantly reduce patients' itching symptoms, improve sleep disorders, and improve patients' quality of life.

Nalfuraphine hydrochloride efficacy

The oral medication is a kappa-opioid receptor agonist that has been shown to be safe and effective in the treatment of HD patients with antihistamine-resistant uremic pruritus. This drug suppresses itching, thereby improving the mental status of HD patients. Nafurafine hydrochloride may be recommended as a promising option for pruritus in HD patients when conventional treatments are ineffective.

Analysis of treatment effect

According to a meta-analysis of two randomized placebo-controlled studies, the results showed that intravenous injection of nalfurapine hydrochloride three times a week can significantly reduce pruritus symptoms in 144 hemodialysis (HD) patients. In this meta-analysis, worst itch, itch intensity, and sleep disturbance were significantly reduced in the nalfuraphine hydrochloride group compared with the placebo group, demonstrating for the first time the antipruritic activity of nalfuraphine hydrochloride in humans.

Japan conducted a large-scale placebo-controlled study to examine the efficacy and safety of oral nalfurapine hydrochloride in the treatment of refractory pruritus in 337 HD patients. 16 All enrolled patients had experienced pruritus that was resistant to antihistamines or moisturizers for 2 weeks within 1 year before the clinical trial. Two daily oral doses of 2.5 or 5 μg nalfurapine hydrochloride or placebo were administered for 2 weeks, and clinical responses were analyzed.

The results showed that the visual analogue score (VAS) of pruritus in the 5 μg nalfuraphine hydrochloride group (n=114) decreased by an average of 22 mm from baseline, and that of the 2.5 μg group (n=112) decreased by an average of 23 mm. These reductions were statistically significant compared with a mean VAS reduction of 13 mm in the placebo group (n=111). When a reduction in VAS value of 50% or more was estimated as significant response, 32.5% of patients in the 5 μg nalfurapine hydrochloride group and 28.6% of patients in the 2.5 μg nalfurapine hydrochloride group showed significant response. In comparison, 17.1% of patients in the placebo group showed significant response. The significant remission rates in the 2.5 and 5 μg nalfurapine hydrochloride groups were significantly higher than those in the placebo group.

Safety Analysis

In a long-term trial, 103 patients (48.8) experienced adverse drug reactions. 6.2% discontinued treatment due to adverse drug reactions. Adverse reactions include insomnia (15.2%), constipation (3.3%), increased blood prolactin (0.9%), drowsiness (1.9%), dizziness (0.9%), itching (0.9%), diarrhea (0.9%), malaise (0.9%), mood changes (0.9%), eczema (0.5%), vomiting (0.5%), anemia (0.9%) and increased blood thyroid-stimulating hormone.

Medication Guide

Nalfuraphine hydrochloride is usually supplied in the form of orally disintegrating tablets, which allows patients to quickly dissolve in the mouth without the need for water. The initial dose is usually 2.5 micrograms per day, which is equivalent to one quarter of an orally disintegrating tablet containing nalfurapine hydrochloride 10 mg. The dose can be adjusted based on patient response and physician judgment. Usually once daily, it is recommended to take it at a fixed time every day to maintain stable blood concentration.