Abstract: Background – Maropitant hydrochloride is labeled for the prevention and treatment of acute vomiting in dogs when administered by subcutaneous (SC) injection. Clinically, maropitant is often injected subcutaneously within a bolus of subcutaneous fluids, however there is only anecdotal evidence this practice is effective.
Hypothesis/Objectives – The objective of this study was to describe the pharmacokinetics of maropitant in dogs when administered as a SC bolus and as a SC bolus combined with SC Lactated Ringers Injection (LRS) fluids.
Animals – Six healthy, adult, purpose-bred Beagle dogs.
Methods – Dogs received maropitant (1 mg/kg) as a SC injection alone and as a SC injection within a SC bolus of 15 mL/kg LRS in a masked, randomized crossover study with a minimum 4 day washout period between treatments. Blood samples were collected at pre-determined time points for 32 hours for maropitant quantification using ultra-high-pressure liquid chromatography/mass spectrometry. Noncompartmental analysis was used to estimate pharmacokinetic parameters. Data were compared using the Wilcoxon matched pairs signed rank test and p < 0.05 was considered significant.
Results – Data are presented as median (range) in Table 1. Except for elimination half-life, the pharmacokinetics of SC maropitant alone or within a bolus of LRS did not differ.
Conclusions and clinical importance – Elimination half-life is longer when maropitant is administered with SC LRS. Further studies are needed to determine if there is pharmacodynamic benefit to maropitant administration within a SC LRS bolus in dogs.
.png)
