A Comparative Study on the Effects of Naltrexone and Loratadine on Uremic Pruritus

Abstract

Background: Two recent studies have provided opposite results on the efficacy of naltrexone on uremic pruritus. We have performed a third study. Objective: To compare the efficacy and tolerance of naltrexone and loratadine in uremic pruritus. Patients/Methods: Among 296 hemodialyzed patients, 65 suffered from uremic pruritus. Fifty-two patients participated in the study. The patients were treated for 2 weeks with naltrexone (50 mg/day; 26 patients) or loratadine (10 mg/day; 26 patients), after a washout of 48 h. Pruritus intensity was scored by a visual analogue scale (VAS). Adverse events were carefully searched for. The two groups were statistically equivalent. Results: There was no significant difference in the mean VAS scores after treatment, but naltrexone allowed a dramatic decrease in VAS scores (Δ >3/10) in 7 patients. Adverse events (mainly nausea and sleep disturbances) were observed in 10/26 patients. Conclusions: Naltrexone is effective only in a subset of patients. Adverse events are very frequent. The differences of efficacy and tolerance between patients might be due to metabolism. Naltrexone might be considered as a second-line treatment.

Chronic kidney disease-associated pruritus: impact on quality of life and current management challenges

“…These studies yielded mixed results. [89][90][91] In a randomized, controlled, crossover study of 15 HD patients, 1 week of naltrexone treatment significantly improved pruritus severity compared to placebo. 49 Two subsequent trials, however, failed to confirm this effect.…”

“…90 In another randomized trial, naltrexone did not significantly improve pruritus compared to loratidine over a 2-week treatment period. 91 Subsequently, peripheral kappa-opioid receptor agonists showed more promising results to treat CKD-aP. The most widely studied kappa-opioid receptor agonist is nalfurafine.…”

A Longitudinal Study of Uremic Pruritus in Hemodialysis Patients

“…For itching intensity, we adapted two scales from those used most widely for quantifying intensity of pain: the 100-mm visual analog scale (VAS) (5-12) and the 11-point numerical rating scale (NRS) (13)(14)(15). The VAS scale already has been used for assessing itching intensity in clinical trials (5)(6)(7)(8)(9)(10)(11)(12). We were interested in comparing patients' ease of use of the NRS with the VAS and in measuring correlations between the two scales.…”

Recent Advances in Treatment for Uremic Pruritus

“…While Peer et al [62] showed in a small placebo-controlled clinical trial that naltrexone, which is a μ-receptor antagonist, is effective, PauliMagnus et al [45] failed to demonstrate any efficacy of naltrexone in the treatment of uremic pruritus. Later, Legroux-Crespel et al [63] conducted a comparative study between naltrexone and loratadine, and concluded that naltrexone is not effective and not well-tolerated because of frequent side effects, except in a small subset of patients. More recently, another perspective was elaborated regarding the use of a қ-agonist, for қ-receptor stimulation inhibits μ-receptor effects both peripherally and centrally, and hence might inhibit itching induced by substance P. In line with this concept, Wikstrom et al [64] conducted two multicenter, randomized, double-blind, placebo-controlled studies that enrolled 144 patients with uremic pruritus to receive post-dialysis intravenous treatment with either nalfurafine, a novel қ-receptor agonist, or placebo for 2 to 4 weeks.…”