Safety and Efficacy of Intravenous Tranexamic Acid for Emesis Induction in Dogs

When a dog accidentally swallows certain substances, such as chocolate or onions, promptly inducing emesis can remove the substance from the dog’s digestive system before it becomes fully absorbed. Traditional emetic agents include apomorphine, which can be administered intravenously (IV) or via conjunctival injection, and oral 3% hydrogen peroxide (H₂O₂). Both agents typically induce vomiting within approximately 10 minutes and have only mild adverse effects.

Tranexamic acid is an antifibrinolytic used in human and veterinary medicine. In humans, it can cause nausea and vomiting. Unlike apomorphine, which stimulates the chemoreceptor trigger zone, and H₂O₂, which stimulates the oropharynx, tranexamic acid induces emesis by stimulating tachykinin neurokinin 1 receptors; these receptors regulate the vomiting reflex.

A previous study reported tranexamic acid’s ability to dose dependently induce emesis in dogs. To date, though, a safety and efficacy profile for veterinary use of tranexamic acid has not been determined. To address this knowledge gap, a Japanese research team investigated the safety and efficacy of IV tranexamic acid for inducing emesis in dogs. Their results were recently published in the Journal of Veterinary Medical Science.

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The research team evaluated the medical records of 137 dogs treated for accidental ingestion. The following information was collected:

• Signalment: age, body weight, breed
• Ingested material: type, amount, location within digestive system
• Tranexamic acid administration: dose, number of administrations
• Emesis description: time to onset, duration, frequency
• Adverse effects

Efficacy

Overall, nearly 95% (129/137) of dogs vomited after receiving IV tranexamic acid (median dose, 50 mg/kg IV). Time to emesis ranged from about 2 minutes after the first dose to nearly 6 minutes after the third dose. On average, the dogs vomited twice after receiving tranexamic acid.

Approximately 85% of dogs vomited after a single dose. Efficacy decreased to about 65% for dogs receiving second and third doses. Some dogs that did not vomit after the first dose did not receive a second dose either because they were only retching or more than 2 hours had elapsed since accidental ingestion. Several dogs that did not vomit after the second dose received either 3% H₂O₂ or no further treatment.

Efficacy did not appear to be affected by age, body weight, or type of ingested material (e.g., chocolate, clothing). However, the researchers suggested further study of the association between these factors and tranexamic acid—induced emesis.

Safety

Adverse effects occurred after the first dose and were reported in only 2 dogs. One dog experienced a tonic-clonic seizure and fully recovered with diazepam treatment. This dog ingested cocoa powder, which contains theobromine, a substance that can induce seizures. Notably, tranexamic acid can inhibit inhibitory neurotransmitters like GABA. Such neuronal excitation could have caused the dog’s seizure. “Further studies are warranted to investigate the proconvulsant effect of tranexamic acid in dogs,” the researchers wrote.

The second dog had bleeding at the IV catheter site. This bleeding may have occurred because dogs tend to be more hyperfibrinolytic than humans, the researchers believed. Applying tape at the catheter site stopped the bleeding.

Conclusions

The researchers determined that tranexamic acid is safe and highly effective at inducing emesis in dogs after a single dose, concluding that “the prompt and short-acting properties of tranexamic acid make it a good choice as an emetic.”

Dr. Pendergrass received her Doctor of Veterinary Medicine degree from the Virginia-Maryland College of Veterinary Medicine. Following veterinary school, she completed a postdoctoral fellowship at Emory University’s Yerkes National Primate Research Center. Dr. Pendergrass is the founder and owner of JPen Communications, a medical communications company.