ASSESSMENT OF THE EMETOGENIC POTENTIAL OF INTRATHECAL CHEMOTHERAPY AND RESPONSE TO PROPHYLACTIC TREATMENT WITH ONDANSETRON

The purpose of this study was to document the emetogenic potential of intrathecal chemotherapy (IC) in children and to evaluate the efficacy of ondansetron in reducing nausea and vomiting with this chemotherapy treatment. Patients less than 18 years of age with acute lymphoblasti c leukemia were eligible to participate in a survey project measuring the emetogenic potential of various chemotherapy treatments. Patients surveyed for 1 or more IC treatments were included in this report, The IC consisted of methotrexate, hydrocortisone and cytarabine, dosed ac cording to patient age. A nausea/vomiting survey instrument was comple ted by each patient and/or parent following IC treatment. The instrume nt rated nausea, vomiting and daily activity interference (DAI) on a 4 -point scale of 0 = none, 1 = mild, 2 = moderate and 3 = severe, and c ollected data on the number of vomiting and/or retching episodes in ad dition to the child's appetite following the chemotherapy treatment. W hen ondansetron was employed, it was administered in an i.v. infusion at a dose of 0.15 mg/kg before and after chemotherapy or as an Oral do se of 4 mg or 8 mg before chemotherapy. Courses of IC without antiemet ics were analyzed to determine the emetogenic potential of IC. For pat ients receiving IC both with and without ondansetron, courses were com pared with each patient used as their own control to determine the inf luence of ondansetron upon survey responses, Statistical analysis cons isted of nonparametric Friedman 2-way ANOVA for ordinal variables and a paired t-test for continuous variables. The binomial test was employ ed to analyze for differences between ondansetron and no antiemetic in the number of patients with complete control of both nausea and vomit ing or vomiting alone, A. total of 63 children with a mean age of 7.6 +/- 4.2 years were each studied on one or more occasions. Thirty-seven children were surveyed for 87 IC treatments without antiemetics (grou p I), and 17 children from this group were surveyed for 48 IC courses with i.v. ondansetron (group IA). An additional 18 children were subse quently surveyed for 39 IC courses with i.v. ondansetron (group II). F ifteen patients (7 of whom were members of group I) were surveyed foll owing 33 IC courses with oral ondansetron (group III). The purvey scor es for group I patients were: nausea severity 1.3 +/- 1.1, vomiting se verity 1.2 +/- 1.1, DAI 1.2 +/- 1.0 and mean number of emetic episodes 4.7 +/- 8.4. The mean appetite score was 1.5 +/- 1.1. For patients in group IA, nausea severity (0.8 +/- 0.9), vomiting severity (0.5 +/- 0 .8), DAI (0.7 +/- 0.8), and the number of emetic episodes (1.4 +/- 2.8 ) were all significantly lower than with prior IC treatments without o ndansetron. For complete protection, children receiving i.v. ondansetr on had greater complete protect-ion rates from both nausea and vomitin g or vomiting alone than did patients receiving no antiemetic. Survey responses were also lower for patients receiving oral ondansetron, but insufficient control data did not allow for statistical analysis. IC results in mild to moderate nausea and vomiting in children. The emeto genic potential of IC is significantly reduced by i.v. ondansetron.