Comparison of the efficacy and safety of zinc sulfate vs. placebo in the treatment of pruritus of hemodialytic patients: a pilot randomized, triple-blind study.

Aim: Improvement of uremic pruritus has been reported under short-term administration of oral zinc sulfate. Objective of the study was to confirm efficacy and safety of oral zinc sulfate in pruritus of hemodialytic patients
Methods: A pilot randomized, triple-blind study was conducted to evaluate the pruritus of hemodialytic patients. Forty eligible patients were screened and assigned to receive either zinc sulfate (220 mg/d) or matched placebo for a 4-week trial. Pruritus scale was evaluated at the initiation of the study and 1, 2, 3, and 4 weeks after the treatment. We used a modified score proposed by Duo assessing pruritus severity, distribution of pruritus, and frequency of pruritus-related sleep disturbance.
Results: Thirty-six patients completed the study. The mean pruritus score decreased in both groups during the first and the second weeks of trial; however, it was more prominent in zinc group than placebo one. In the zinc group, 4 (20%) patients showed pruritus discontinuation during treatment period whereas, in the placebo group, the number was only 1 (5%) patient. Nonetheless, T-test revealed no statistically significant difference between the zinc and placebo groups (P=0.88 and P=0.56, respectively).
Conclusion: Our findings demonstrated that oral zinc sulfate (220 mg/d) during four weeks treatment might be safe and effective in discontinuation of uremic pruritus, but it was not significant. This could be because of the small number of patients; therefore, we suggest conducting more studies with larger sample size.