Ondansetron therapy for uremic pruritus in hemodialysis patients

Pruritus is a distressing symptom affecting up to 90% of dialysis patients. Conventional treatment with antihistamines is often ineffective and may ha ve unacceptable side effects, Serotonin (5-hydroxytryptamine type 3 [5-HT3] ) is known to enhance pain perception and pruritic symptoms through recepto rs on sensory nerve endings. Antagonism of 5-HT3 receptors may be of use in treating uremic pruritus, We randomly assigned 16 hemodialysis patients wi th persistent pruritus to treatment with the 5-HT3-receptor antagonist, ond ansetron (8 mg), or placebo three times daily for 2 weeks each in a prospec tive, placebo-controlled, double-blind crossover study, Patients scored the ir intensity of pruritus daily on a 0-to-10 Visual analogue scale (0 = no p ruritus, 10 = maximal pruritus), and daily use of antihistamines as escape medication was recorded, The median daily pruritus score did not change sig nificantly during active or placebo treatment (preondansetron, 5.3; interqu artile range [IQR], 3.4 to 6.3; during ondansetron, 3.9; IQR, 2.7 to 5.0; P = not significant; preplacebo, 3.7; IQR, 3.0 to 4.6; during placebo, 3.6; IQR, 2.4 to 4.8; P = not significant). The median daily percentage of escap e medication use decreased from 21% (IQR, 9 to 61) to 9% (IQR, 0 to 33) wit h ondansetron (P = not significant) and from 53% (IQR, 0 to 88) to 5% (IQR, 0 to 31) with placebo (P = not significant). There was no difference in pr edialysis biochemistry test results or dialysis efficacy during treatment p hases, Ondansetron does not improve pruritus in hemodialysis patients. Use of antihistamines decreased with both ondansetron and placebo. (C) 2000 by the National Kidney Foundation, Inc.