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 have unacceptable side effects. Serotonin (5-hydroxytryptamine type 3 [5-HT(3)]) is known to enhance pain perception and pruritic symptoms through receptors on sensory nerve endings. Antagonism of 5-HT(3) receptors may be of use in treating uremic pruritus. We randomly assigned 16 hemodialysis patients with persistent pruritus to treatment with the 5-HT(3)-receptor antagonist, ondansetron (8 mg), or placebo three times daily for 2 weeks each in a prospective, placebo-controlled, double-blind crossover study. Patients scored their intensity of pruritus daily on a 0-to-10 visual analogue scale (0 = no pruritus, 10 = maximal pruritus), and daily use of antihistamines as escape medication was recorded. The median daily pruritus score did not change significantly during active or placebo treatment (preondansetron, 5. 3; interquartile 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 escape medication use decreased from 21% (IQR, 9 to 61) to 9% (IQR, 0 to 33) with 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 predialysis biochemistry test results or dialysis efficacy during treatment phases. Ondansetron does not improve pruritus in hemodialysis patients. Use of antihistamines decreased with both ondansetron and placebo.