Background: Pruritus is one of the most common problems in patients suffering chronic renal failure. Twenty five - 35% of predialysis patients and 60-80% of patients during dialysis complain pruritus. The exact pathophysiology of pruritus is unknown; however, some possible interactive factors include: histamine release from mast cells and basophiles, uremic skin, cutaneous mast cells proliferation, adipose cells atrophy, electrolyte imbalance, and accumulation of bile acids. Since histamine is the main proposed mediator in pruritus, the goal of this study was to evaluate the role of antihistamines in controling of pruritus of patients with chronic renal failure. This study was done as a before - after study during one year period in dialysis department of Imam Khomeini hospital.

Methods: Thirty patients complied with inclusion criteria were entered in the study. Treatment strategy was: 2 weeks treatment with hydroxyzine 25 mg TDS, followed by one week wash-out period, then 2 weeks ketotifen therapy 1mg BID and finally two weeks treatment with chlorpheniramine 4mg BD following one week washout period after ketotifen therapy. Pruritus severity before and after each treatment period was evaluated with Pruritus Severity Score (PSS) chart.

Results: The mean PSS reduction by hydroxyzine, ketotifen and chlorpheniramine, were 33%, 4.5% and 20%, respectively.

Conclusion: PSS improvement with hydroxyzine and chlorpheniramine was statistically significant (p<0.001). However, ketotifen induced pruritus reduction was not considerably significant.