The Dog Seizure Medication You May Not Have Heard Of (Yet)
Years ago, I attended a canine epilepsy online conference put on Vet Vine. It was an amazing conference and I learned so much. One of my takeaways was regarding a dog seizure medication called imepitoin (also known by the brand name Pexion). I had never heard of it before because at that time it was not an option for use in the United States. But when I began to dig in, I realized imepitoin might offer something unique—especially for dogs who struggle with side effects. After years of being used successfully in Europe, it’s now available at this time for off-label use by veterinarians in the U.S.
In this post, I’ll walk you through what imepitoin is, how it works, and who it might help.
What Is Imepitoin & Where It’s Used
Imepitoin is an anti-seizure (antiepileptic) drug that has been approved in Europe to treat idiopathic epilepsy in dogs. Its mechanism is distinct: imepitoin acts as a partial agonist at the benzodiazepine site of the GABAA_AA receptor, meaning it gently mimics GABA’s effects to calm over-excited electrical activity in the brain. It also has some mild effect on calcium channels, which can further help stabilize neuronal activity.
What the Research Shows (Strengths & Limitations)
From what I found, imepitoin has several interesting advantages:
In clinical trials, dogs treated with a higher dose (30 mg/kg twice daily) showed a significant reduction in monthly seizure frequency compared to lower doses. PMC
Many dogs remained seizure-free for generalized seizures (in those trials). PMC
It tends to be well tolerated, with fewer severe side effects in many cases. European Medicines Agency (EMA)+4PMC+4PMC+4
It has been studied as an add-on to phenobarbital in dogs whose seizures are harder to manage; this combination has shown promise in reducing seizure frequency. PubMed+2BioMed Central+2
But there are some important caveats and limits:
Imepitoin is not always the best choice for dogs with cluster seizures or status epilepticus (continuous or repeated seizures). European Medicines Agency (EMA)+1
Because it is newer in many regions, availability may be limited.
Some mild side effects have been reported
Because it’s relatively newer, long-term data in many dog populations is more limited compared to older drugs like phenobarbital or bromide.
Who Might Benefit from Imepitoin?
Based on what I found, imepitoin might be more suited for:
Dogs with milder seizure frequency (not frequent clustering)
Dogs who tolerate other medications poorly or have side effects
Owners looking for a drug with a potentially gentler side-effect profile
Dogs in regions where imepitoin is legal and accessible
Your veterinarian will consider whether your dog’s seizure pattern, other health conditions, and region make it a sensible option.
My Take: Why It Deserves a Spot on Your Radar
Imepitoin isn’t a replacement for established medicines like phenobarbital or levetiracetam—but it is an intriguing, gentler option for many dogs, especially those who struggle with side effects or have milder epilepsy. The fact that it’s now being studied more, used in combination protocols, and has a growing body of evidence makes it something every pet parent should know about.
If you’d like help learning about other medication options, preparing questions for your vet, or building a medication plan that gives you confidence, my course My Dog Was Diagnosed With Epilepsy – Now What? is tailored exactly for this.