Background: Breakthrough CT-induced nausea and vomiting (CINV) may increase resource needs, eg, hydration. GERSC (SUSTOL) + other antiemetics prevent CINV associated with MEC or anthracycline + cyclophosphamide–based therapy. This retrospective analysis evaluated CINV-related hydration in pts treated with PALO or GERSC antiemetic therapy. Methods: Pts at a multisite community practice had MEC or HEC and a 3-drug antiemetic regimen: NK-1 receptor antagonist (RA), dexamethasone, and 5-HT₃ RA (PALO only, GERSC only, or PALO then GERSC). CT emetogenicity (HEC, MEC), number of cycles, and CINV-related hydration were extracted from medical records. Hydration rate (events per cycle) was analyzed for pts who had PALO vs GERSC (group 1; nonparametric 2-sided Wilcoxon rank sum test) and pts who had PALO then GERSC (group 2; paired t-test). Results: There were 93 PALO, 91 GERSC, and 48 PALO-then-GERSC pts. Group 1 had mean (SD) CT cycles of 5.4 (2.8) on PALO vs 4.1 (2.2) on GERSC. The whole group (P<.0001) and HEC subgroup (P<.0001) had significantly higher hydration rates with PALO vs GERSC (Table). Overall, 22% (PALO) vs 58% (GERSC) of pts had no hydration. In HEC/MEC subgroups, respectively, 19%/33% (PALO) vs 60%/56% (GERSC) of pts had no hydration. Group 2 switched pts had mean (SD) 3.5 (3.2) cycles on PALO vs 3.1 (2.2) on GERSC. All pts and MEC subgroup had no differences in hydration rate with PALO vs GERSC. HEC subgroup hydration rates were significantly higher for PALO vs GERSC (P=.028; Table). Conclusions: In a multisite practice, CINV-related hydration was ~3 times less per CT cycle for pts receiving GERSC vs PALO as part of a 3-drug antiemetic regimen. Pts on HEC and treated with PALO then GERSC had significantly reduced hydration needs with GERSC. Reduced hydration needs may improve quality of life and simplify pt management.

*P<.0001 vs PALO ^†P=.028 vs PALO