Nausea and vomiting in fractionated radiotherapy: a prospective on-demand trial of tropisetron rescue for non-responders to metoclopramide.

A prospective trial was performed to better assess the risk of nausea and vomiting and the rescue value of
tropisetron (TRO), a 5HT3 receptor antagonist, in 88 patients undergoing fractionated radiotherapy to the
abdomen or to large supradiaphragmatic fields and failing a first anti-emetic trial with metoclopramide (MET).
Nausea was graded 0 (absent), 1 (mild), 2 (moderate) and 3 (severe). Nausea requiring anti-emetics (L grade 2)
was present in 64% of the patients. MET was able to control nausea (I grade 1) in 26 of 58 patients (45%) who
developed 1 grade 2 nausea during radiation treatment (2 patients vomiting without nausea included). 34 patients
required TRO, and 31 experienced immediate relief. However, nausea (1 grade 2) recurred in 7 patients from 1
to 3 weeks after starting, TRO. Sex, age, field type and field size (cm*) did not influence the incidence and severity
of nausea and vomiting. Only 24188 patients vomited after starting radiotherapy. MET helped to eliminate emesis
in one third of these patients. TRO helped to control vomiting in 73% of the salvaged patients. Constipation was
observed in 8 patients on TRO and was a reason to stop the medication in 4 cases.