Discussion
In this study, the postoperative administration of vestipitant
wasno different fromondansetron 4mgi.v. in surgical patients
with PONV after failed ondansetron prophylaxis. This was observed
at all doses of i.v. vestipitant, ranging from 6 to 36 mg.
The primary endpoint for efficacy was the rate of patients exhibiting
complete response, defined as no emesis and no further
rescue medication from10 min post-infusion up to 24 h or hospital
discharge. The complete response rate for all doses of vestipitant
combined was 56% compared with ondansetron at
42%. However, vestipitant was superior to ondansetron in decreasing
the episodes of postoperative emesis and retching.
It should be noted that the patient population for this trial
was predominantly women. However, this limitation is a
logical consequence to the eligibility based on the Apfel risk
score15 reflecting the population most at risk for PONV.
However, there is no convincing evidence that the response
inmenwould be different with respect to antiemetic response.
The difference in response would most likely be due to the differences
in the control event rate in prevention studies.
The NNRS scores and the times to PONV or discharge were
similar between the vestipitant and ondansetron treatment
groups. In addition, administration of vestipitant andondansetron
in these surgical patients was safe and well tolerated with
a low number of adverse events.
Although several strategies are available for the prevention
of PONV, there are fewer effective treatment options after the
onset of PONV.16 17 This is primarily because of the difficulty
of conducting interventional trials for PONV. Owing to the
difficulty in predicting PONV after failed prophylaxis, these
studies require screening a large number of patients, of
which a small proportion may subsequently experience PONV
and become eligible for enrolment into an interventional
trial.16 17 Furthermore, the pharmacodynamic features of the
available preventive agents are different and some (such as the study by Kovac and colleagues, there is good reason to
assume that ondansetron in the study by Diemunsch and colleagues,
18 Candiotti and colleagues,10 and in the current study
had some effect and could have been better than placebo had
placebo been tested.4