A comparative study on the effects of naltrexone and loratadine on uremic pruritus.

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 (Delta >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.