Drug Des Devel Ther. 2026 Jun 23;20:609499. doi: 10.2147/DDDT.S609499. eCollection 2026.
ABSTRACT
BACKGROUND: Prophylactic antiemetics are routinely used in gastrointestinal surgery. This study investigated whether granisetron pretreatment alters norepinephrine requirements for preventing post-induction hypotension in elderly patients.
METHODS: In this randomized double-blind trial, 64 patients (60-74 years) undergoing laparoscopic gastrointestinal resection received intravenous granisetron (3 mg) or saline placebo before induction. The 50% effective dose (ED) of norepinephrine to prevent hypotension (>20% decrease in mean arterial pressure) within 30 min post-induction was determined using the up-down sequential method, with probit regression as confirmatory analysis.
RESULTS: Baseline characteristics were comparable between the two groups. The up-down sequential analysis revealed that the ED of norepinephrine was significantly lower in the granisetron group (0.037 μg/kg/min [95% CI 0.031-0.040 μg/kg/min]) than in the control group (0.049 μg/kg/min [95% CI 0.043-0.052 μg/kg/min]) (P < 0.001) representing an approximate 24% reduction. This finding was supported by probit regression analysis, which estimated ED values of 0.040 μg/kg/min [95% CI 0.033-0.051 μg/kg/min] and 0.052 μg/kg/min [95% CI 0.045-0.064 μg/kg/min] for the granisetron and control groups, respectively. No significant difference was observed in the incidence of postoperative nausea and vomiting between the two groups.
CONCLUSION: Granisetron pretreatment significantly reduces the ED of norepinephrine required to prevent post-induction hypotension in elderly patients by approximately 24% indicating a pharmacodynamic interaction consistent with enhanced vasopressor efficacy. These findings indicate that pre-induction antiemetic administration may represent a potentially favorable timing strategy.
PMID:42371482 | PMC:PMC13310409 | DOI:10.2147/DDDT.S609499