Department of Internal Medicine, Provincial Nantou Hospital, Nantou;
Division of Gastroenterology, Department of Internal Medicine,
Veterans General Hospital-Taipei;
National Yang-Ming University School of Medicine, Taipei, Taiwan, R.O.C.
| The objective of the present study was to determine
the effect of ondansetron, a specific serotonin type 3 (5-HT3) receptor antagonist, to relieve cholestatic pruritus in patients resistant to conventional antipruritic therapy. In a placebo-controlled study the acute effect of an intravenous injection of ondansetron or placebo (normal saline) was tested in 12 cancer patients (mean age 61¡Ó 8.8 yr) with cholestatic itch. Each patient received ondansetron (8 mg and 4 mg) and placebo infusion consequently. The intensity of pruritus was assessed by a visual rating scale from 0 to 10 (most severe pruritus). A successful treatment was regarded when the intensity was reduced by 50% or more within 2 hours after injection of ondansetron. During the following 24 hours, the patients were assessed and the time point recorded when the intensity of pruritus relapsed into the same degree as pre-treatment. Intravenous application of ondansetron abolished pruritus within 60 min by a 50% reduction of the intensity of itching. The effect of ondansetron on itching intensity showed significant difference (p< 0.001) from placebo during a controlled observation period from 30 to 120 minutes. The onset of a successful treatment (18.3 ¡Ó 6.2 vs 36.8 ¡Ó 21.4 min, p< 0.05) and the duration (8.3 ¡Ó 1.3 vs 4.0 ¡Ó 1.0 hours, p< 0.01) were significantly earlier and longer at a high dose. No side effects occurred during treatment. Our findings suggest that the 5-HT3 receptor antagonist may be a novel therapeutic alternative for the treatment of cholestatic pruritus. |