Prospective, controlled, blinded, randomized crossover trial evaluating the effect of maropitant versus ondansetron on inhibiting tranexamic acid-evoked emesis.

Abstract

OBJECTIVE: To evaluate the incidence of tranexamic acid (TXA)-induced nausea and vomiting after the prophylactic use of 2 antiemetics, ondansetron and maropitant, compared with saline. DESIGN: Prospective, blinded, placebo-controlled, randomized, crossover study. SETTING: University research facility. ANIMALS: Eight adult, purpose-bred Beagles. INTERVENTION: Dogs received 3 treatments on 3 occasions with a 3-week washout period. Either maropitant (1&#xa0;mg/kg), ondansetron (0.2&#xa0;mg/kg), or saline solution was given intravenously in equal volumes, followed 10 minutes later by 50&#xa0;mg/kg IV TXA. A blinded observer evaluated the dogs for signs of vomiting and nausea for 30 minutes. The severity of nausea was assessed with a visual analog scale (VAS) and recorded at baseline before TXA, and at the end of 3 observational periods: 0-5, 5-15, and 15-30 minutes after TXA. A generalized linear mixed effect model was used to assess for group and period effects. Statistical significance was set at. MEASUREMENTS AND MAIN RESULTS: None of the dogs vomited after maropitant. Emesis occurred in 5 out of 8 dogs (62.5%), a median (range) of 1 time (1-2) after ondansetron and 1 time (1-3) after saline. There was a significant effect on vomiting of maropitant against saline (P&#xa0;<&#xa0;0.0001) but not for ondansetron against saline (P&#xa0;=&#xa0;0.53). The highest nausea VASs were recorded during the first 5 minutes after TXA with a significant reduction of VAS variability in the maropitant group (P&#xa0;=&#xa0;0.003). The effect of maropitant and ondansetron against saline on the severity of nausea was not statistically significant (P&#xa0;=&#xa0;0.069). CONCLUSION: The neurokinin 1 receptor antagonist maropitant at the dose used, administered IV 10 minutes before 50&#xa0;mg/kg TXA, was effective in preventing vomiting compared with ondansetron and placebo. Our results support the prophylactic IV administration of maropitant in dogs that are scheduled to receive TXA.