Results
Of the 124 patients initially screened through pharmacy dispensing
records, 88 were excluded. The most common reasons for exclusion were
olanzapine use as part of a four-drug CINV regimen, chemotherapy as part
conditioning regimen for transplant, or chemotherapy was classified as
moderately emetogenic. A total of 36 unique patients and total of 82
chemotherapy blocks met inclusion criteria. Baseline characteristics and
demographic data are presented in Table 1. In the acute phase, CR was
achieved in 22 (52%) patients in the olanzapine group versus 25 (63%)
in the dexamethasone group (p=0.354). There was no clinically or
statistically significant difference in CR rates between olanzapine and
dexamethasone groups (Table 2).
Ondansetron 0.15 mg/kg (maximum 8 mg) every 8 hours was the 5-HT3
antagonist used in all but two of the chemotherapy blocks in the
dexamethasone group. Palonosetron 0.02 mcg/kg (maximum 0.25 mg) for one
dose was administered to those that didn’t receive ondansetron.
Fosaprepitant was dosed per package insert for one dose and one patient
in the olanzapine group received two doses of fosaprepitant 72 hours
apart. In the dexamethasone group, dexamethasone was dosed at 5 mg/m2
once daily for the duration of chemotherapy.
The mean initial olanzapine dose was 0.07 mg/kg/dose (range 0.02-0.1,
maximum 5 mg). Doses were rounded to nearest 1.25 mg. The median
duration of olanzapine was 2 days (range 1-7 days). Olanzapine was
initiated on day 1 of chemotherapy for all blocks and was continued for
the duration of each chemotherapy block or longer in 28 (67%) blocks.
No patients required a dose reduction of olanzapine due to intolerance;
3 patients required a dose increase to maximize efficacy. Olanzapine was
discontinued in one of two patients for over-sedation.