pexion canine epilepsy

A New Treatment for Canine Idiopathic Epilepsy: Pexion

We recently wrote about canine idiopathic epilepsy, a form of epilepsy where the cause remains unknown. Today we are looking at a new treatment; Pexion.

The severity of epilepsy can vary greatly between individual sufferers. Some dogs may experience a single, isolated seizure, whilst other can experience multiple seizures every week.

Recently Boehringer Ingelheim has announced their latest product for the treatment of canine epilepsy, Pexion® (Pexion) an alternative to the traditional phenobarbital or potassium bromide treatments given to epileptic dogs.

Are you using Pexion?

If you’re dog has been prescribed Pexion, let us know how your dog is getting on in the comments below. Join the discussion and keep the community updated with your progress.

What Is Pexion?

Unlike other treatments for canine epilepsy, Pexion contains the active ingredient Imepitoin. Imepitoin acts in a similar manner to previous anti-epileptic medicines, potassium bromide and phenobarbital, in that it works to suppress electrical activity in the brain.

Imepitoin partially activates GABA receptors, which are responsible for reducing electrical activity between nerve cells. This partial activation of the GABA receptors is believed to reduce electrical activity and help prevent seizures. Specifically, Imepitoin also has a weak blocking effect on calcium channels that allow electrical signals to be propagated along nerve cells.

See here for more information about Pexion 

Does Pexion Work?

A study conducted on Pexion during its development compared it to the traditional anti-epileptic medicine phenobarbital. A 20 week study of 226 dogs taking the medications found Pexion matched phenobarbital in efficacy, reducing the occurence of seizures by around 50%. 1

Is Pexion a Better Alternative?

The Pexion study showed that it had an effectiveness equivalent to phenobarbital, however, Pexion may be considered a better alternative as it has less severe side effects.

Unlike phenobarbital, Pexion does not pose a hepatotoxicity risk (liver toxicity). This means the regular testing required to ensure that a dog’s liver remains healthy is not needed whilst being given Pexion.

Treating the Epileptic Dog

It is commonly cited that around 0.5 to 5% of dogs suffer from some form of epilepsy, the severity varying between breeds and individuals. In dogs where seizures occur infrequently  owners may consider not using any medication at all, avoiding the side effects associated with anti-epileptic medications.

In dogs where seizures occur more freqently, such as once a month or more, treatment should be considered.

The introduction of Pexion gives owners and vets a greater choice when it comes to treatment, but does not replace phenobarbital and potassium bromide.

Owners should consult their vet and explore all the possibilities when dealing with an epileptic dog.

Seizure Types That Require Immediate Veterinary Assistance

Cluster seizures – When multiple seizures occur in one 24 hour period
Status epilepticus – A persistent epileptic state that lasts for longer than 5 minutes

For more information about epilepsy, such as the causes, what to do during a seizure and more, see this article.

Disclaimer: This article was written as a response to the release of Pexion and as a follow up to a previous article concerning idiopathic epilepsy. I am not affiliated with the product (Pexion) or the manufacturer (Boehringer). 

Featured Image: Onkel_wart

About James Watts

BSc Bioveterinary Science. Editor of PetSci. When I'm not writing, learning, discussing, or reading about animals, you know it's the weekend! Currently developing PetSci HealthTrak, the fast and easy way to monitor your pet's weight and calorie intake. HealthTrak offers a simple way to track your pet's progress, helping them achieve a healthy weight and a long, happy life.

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  1. My staffy x has been on Pexion now for about six months, after being on phenobarb for two years. No discernible side effects and she’s been seizure free. the only slight difficulty with Pexion is that the pills are much larger than the phenobarb pills, so it’s not so easy to give them to her. Otherwise, no problems at all, although the overall cost of the medication is about two hundred dollars a year more than the phenobarb/blood test routine.

  2. My Chocolate has been under medication on phenobarb and pexion for almost 2 years. His condition becomes more stable and controlled. I want to thanks so much of my Vet introducing pexion to me.

  3. My Pomaranian is on Pexion for 10 months now, and he’s given 2 times 200 mg a day. He had several seizures before we started medicating him, because the seizures were rather mild when he started. But then the seizures came quicker and we started with Pexion.
    At that point, when he got a seizure he had clusters of 4 seizures within 24 hours. He never had clusters before. My vet neurologist added Levetiracetam, and now he is almost 4 months seizure free. We are going to try to ween him off the Pexion now.

    • My Springer clustered from the beginning and was put straight on Pexion. She went two months seizure free and the next clusters were slightly less. They upped the meds and we went 28 days and the next clusters were within minutes of each other but had reduced from 4 to 2. They upped the Pexion to 600mgs twice daily and added Keppra. So far we’re a few days short of 3 months seizure free. I’m not looking to reduce or change anything at the moment as this is the longest she’s gone.

  4. My Beagle, Daisy, is 8 years old. She had her first seizure at 6 yrs old, when she had a cluster of 5 within 36 hours. Each one left her very distressed, panting, crying and wanting close contact with us, but unable to settle. She would come to us then wander away for a few yards and immediately come back again for reassurance. This would sometimes last for more than an hour before she would eventually settle down and rest.
    The vet put her on Epiphen and she was fine for 6 months before she had another cluster. These seizures seemed more severe than the first cluster and the vet increased the epiphen from 1 1/2 to 2 tablets twice a day. The next cluster came after only 3 months at which point the vet added Pexion to her medication. She has (thankfully) had no more seizures since, but last year she became really ill and was diagnosed with pancreatitis. We now feed her a really low fat diet (Not that she was given a fatty diet before) but wanted to cut down on the Epiphen if possible because we feel that this is what causedf the pancreatitis. The vet however, says that Pexion is just as toxic as Epiphen. We really don’t know what to do for the best. She is not underweight, but is forever searching for food. She will do anything to reach anything edible, including quick snatch manoeuvres if you look away for a few seconds…..even a cup of tea…..or a pair of leather gloves. She has always been a bit of an opportunist, but has become so determined since being on the low fat diet. Any suggestions on the way forward?

    • Dear Anne
      A natural thing to use to help protect the liver is Milk Thistle, get it in a tincture and use half the dose for med and small dogs and full dose for larger dogs. It is completely natural but run it by your vets first. Good luck.

    • My Springer has been a disaster with food since being on Pexion. She’ll get into the bin bags, will jump at the kitchen surfaces to get food off a plate, and will bark constantly if not getting anywhere. She also steals food off our lab if she can. She’s also more thirsty. She is overweight so is on a diet but stealing food doesn’t help with the weight management. It’s my understanding that Pexion doesn’t cause the damage the most of the other drugs do so I’m not sure why your vet is saying its toxic. Since adding Keppra alongside the Pexion she’s had no seizures for three months. She clustered from the start but Pexion was the vets preferred choice even though it’s not been trialled in dogs that cluster. It might be worth getting a second opinion with the meds but the hunger is definitely a side effect.

      • my dog is on EPILEASE KBR does anyone else have any dogs on this? and how do they find it? my dog seems to fit once a month

        • Hi Carole – I have some Epliease that I’m not using – please email me and I can send to you if you are UK

        • Hello Carol.

          Shani is on kbr but she is oalso on phenobarbital and gabapentin. When the kbr was added she became very ataxic, nauseous and occasionally vomited. But giving it twice a day, always with food and separately from the pheno she has done wel on it. She is now 37 weeks seizure-free.

          It may br that your dog’s dose might need increasing a little.

  5. my 17 week old whippet has just had 3 seizures over the course of 2 weeks, 2 of which within 36 hours. The vet immedicatley prescribed 100mg Pexion x 2 per day based on his weight, nutritional supplements x 2 per day and emergency diazepam in case of another seizure. He has been on this medication for 4 days now. The main side affectes are increased hunger, thirst, excessive weeing and hyperactivity. I’m hoping that these side affects will settle in time which according to the drug information they should. He has so far not had another seizure but I find it hard to see these changes in him. Other than that he is just his normal lovable self.all of these side affects are however nothing compared to his seizures and at least aren’t causing potential harm so i’m very thankful for that.

    • Pexion is a good starting point but not recommended for clusters. Have you had tests to rule out shunts or infections . Seems very young . I have 5 whippets and Bo developed epilepsy after a vaccination. Love to you and your pup
      Please join Blu Tale foundation group on Facebook

  6. My 4 year Westie has had mild fits since October 2015 he has been on Pexicon for a month now & he has had his first fit since taking Medes this morning.

  7. Sarah, is that good or bad? How often were they happening before starting meds? Was it the same as before or more severe?

    Are you pleased or unhappy about it?


    • When Bailey started having fits they came about one every two to three weeks,I didn’t even recognise them has fits as he didn’t collapse or shake he just ran around disoriented & then sat down for about five minutes looking dazed & confused after about ten minutes he was fine. It was only when I read about epilepsy in dogs that I realised the symptoms were the same & I took him to the vets. The vet advised me to monitor him & if he had more bring him back. Over Christmas 2015 he had two more attacks he had been having them on & off for about three months now. I waited until his next fit before taking him to the vets as I was reluctant to put him on medication after hearing bad things about one of the tablets used to treat epilepsy with this episode of epilepsy he had sickness that lasted three days he wasn’t voluntary being sick he was eating grass to make himself sick. Whether or not this was related to epilepsy I don’t know so I took him to the vets were he put him on anti sickness tablets & told me about Pexicon. My dog took to it well with no side affects other then being extra hungry & more lively,he didn’t have a fit for over 4 weeks when he had one yesterday morning although the whole episode lasted about ten minutes it seemed slightly more severe then before as the shaking was worse.

  8. I have 3 dogs. When I get up in morning they all expect to be fed. I feed two and give other her pexion tablet. She has to wait half hour before eating her breakfast and gets a bit distressed waiting.
    Can I give her her tablet earlier than half an hour as could do this without disturbing other dogs?

    • I’ve never been told to leave it half an hour. I’ve always given to her in her food. She wouldn’t take it otherwise. She’s been seizure free for over 4 months now.

      • I was always told to,give Pexion on an empty stomach so always gave it an hour before I fed my dog.

        • My springer would be going mad if I made her wait that long. She’s very good orientated and she knows the time as asks for breakfast. It’s the first thing I do when I get up. I’ll take a look at the leaflet as I’ve honestly not been advised to wait before eating. I’m not sure what difference it makes but as we went from clustering to where we are now I’d be nervous if changing the routine.

        • I was told not to give Bailey his tablet on a full stomach because the tablet will sit in the food instead of travelling straight to the brain, he can take the tablet either in a treat or piece of ham or cheese but not with a full meal. He can’t have anything to eat an hour before his tablet & I think half an hour after.

  9. According to the neurologist it’s no big deal to give Pexion together with his food. I always crush the Pexion and give it in my dog’s food. No problem.

    • That’s good to hear. Thank you. 😊

    • You just do what works for you dog.

      My dog did really well on Pexion for two years, regularly going 6 months without seizures, but after two years it stopped working so we had to swap him over to Phenobarbital.

      • She’s been on Pexion since July and they added Keppra 5 months ago. With no seizures for 4 months I’ve reduced the Pexion by 200 on each dose. What’s nice is that she seems more with us. Her eyes aren’t as glazed and she doesn’t look beyond us now. It’s also reduced her thirst. I’ve also managed to get her to lose some weight even though Pexion caused her to become hungry all the time. The vet was anxious about reducing it but again sometimes you have to follow intuition.

      • Here the same. Pexion is not working for my dog after 1 1/2 year. He got a cluster yesterday, after being seizure free for 4 months. Now the seizures come every month, gm, and focal seizures every 2 weeks. At this moment i’m waiting for an answer from the neurologist, which meds we must give to decrease the amount of seizures. Very disappointing.

      • Couldn’t agree more, every single dog is unique and the epilepsy is different in every one. A healthy Raw diet and natural remedies such as Bachs rescue remedy stand side by side with conventional remedies. Working with your vet slowly adjusting medication to find what works for your dog. My wonderful vet helped all she could, even with prescription costs by letting me buy my meds from Petdrugsonline that are nearly half vets prices. Unfortunately my furbabies epilepsy was so aggressive we lost the battle when she was nearly 4 years old, a 3 year battle that was worth every day with the best behaved and most beloved border collie Izzy.
        Good luck all of you trying so hard for your dogs, I feel for you with all my heart, remembering the delibilitating fits. Xxx

        • I agree with your comments about a raw diet Amanda. My dog has been on raw for 3 years and I’m sure this helps control his epilepsy, as it can’t be good to feed kibble full of additives, colours and preservatives.


  10. We have a Bassett hound he started having seizures at the age of 2 gradually they became more frequent and he was having a fit every month. We held back on medication until one fit lasted 2 hours and we did not think he would. Come out of it. Our vet prescribed pexion half tablet in a morning half at night so far no fitting after a week he seems to be drinking a little more but no other unusual things happening so far.

  11. Hi my shitzu sassy has just started with the pexlon and i see by your comments their appetite has increased? Well sassy seems to of decreased and shes off her food is this normal she only been on them a couple of days but shes right off her food just wondering if this is normal could anybody advise me please

    • Hi Angela, I must admit I haven’t heared anyone else mention their dogs loosing their appetite & it’s not one of the side affects listed so I think if it carries on you should definitely have it checked out by the vet. I know at the beginning of treatment the vet needs to know as much information as they can get as this is a new drug they might not have the dosage right. So it is worth visiting your vet I case he needs to adjust the dosage or maybe give another madication to work alongside the Pexion. Hope this helps please keep me updated.

  12. Started using pexion about 10 days ago on Bob the springer spaniel. He was put on this as he suffered fits during excercise on 2 occasions 2 months apart. Since he has been on pexion I can’t even walk him for 10 minutes without him stumbling like he is drunk. After 3 minutes on the park this morning he fell over and I had to carry him back. This only happens during excercise never at home. Does anybody have any advice please

    • Sorry I just need to ad. This is now happening every day

    • Hi Paul,

      My Springer has had weakened back legs since she started Pexion in July last year. I notice it more when she’s running around and it’s worse if she jumps in the back door or runs up the stairs. I’ve noticed separately that her joint pops in and out of the socket when walking, which I know is something different, so that might be the cause rather than the Pexion. It’s still early days though and the side effects may start to wear off. I would go back for advice though as it may be that Pexion isn’t the right medication. There are many different types to try. The other main side effects are excessive drinking and hunger but each dog is different. I hope the effects become minimal but do seek advice.

    • Hi Paul, whatever his age is, it’s not normal that a dog can’t walk for 10 minutes without stumbling after he is put on Pexion. Believe me, even with Pexion, this is not a normal behaviour. I would go back to your vet and let him examine another time, maybe even better, ask for a second opinion.

      • We did go back to our vet who advised waiting for at least half an hour after his tablet before we walk him. That makes no difference. We are going to try him without the tablets for a day or two to see if he improves.

        • You must NOT stop the tablets unless advised by the vet. This could trigger just the opposite effect and cause clusters. There are few medications for epilepsy where you can just stop it for a day or two without risking increased seizure activity and that is potassium bromide (aka kbr, Libromide, Epilease). The lameness could be a completely separate issue and I think your vet is just appalling in his response. Time for a new vet or at least a second opinion.

          • Thanks for your advice it’s just hard not to try things. He’s had 2 seizures 2 months apart and now since the tablets he is collapsing every day after a 5 minute walk. He had a better life not being treated. All you seem to get from the vets is that he’s on the right dosage and we should walk him normally and treat him no differently.

          • My boy has his tablet at 8 am and I would not consider taking him anywhere until at least 10.30am. Around about 9 am he is very dopey and just falls asleep. Having said this reading all comments etc I would definitely get a second opinion

          • That actually reassures me slightly. I’ve not tried walking him at a later time. I will give it a go.

          • One other thing that has come to mind , do you give him his tablet on an empty stomach and wait for at least half an hour before giving him his breakfast?

          • Yes I always give him them on an empty stomach.

          • Paul, I do understand the wanting to try things. My dog, Shani, a miniature Dachshund, is my fifth epileptic so I really do understand. But messing with the medicaiton is one thing NOT to try. Saying that, I would be wanting to try a different medicatition. It can take a long time to get the mix of meds right – it took me 18 months to get Shani to a fairly steady rate of fits. With a third added a logn time later she is now 48 weeks since her last seizure.

            I would strongly recommend joining and talking to people worldwide who face epilepsy all the time with their dogs.

          • Hi jean, thanks for the advice. I just find it really frustrating. The first vet we saw at the practice after bob had his fit just gave him Valium and sent my wife home. I then went into see him and advised I wanted more than that so they gave him blood tests. The blood tests came back all clear of liver problems etc. We then asked what the next step was and we were advised to write down in a diary of when the fits happen. Again I didn’t settle for this as I advised him the dates of the fits. He then shrugged his shoulders and said he must be epileptic and put him on pexion. Since the tablets he can’t walk for more than 5 minutes at pace. He is gone around the house. I then went to see the main vet at the practice on Monday night who advised try taking the tablets at different times. These vets are not filling me with confidence I’m even doubting there diagnosis. This is why o wanted to try him off the pexion for a couple of days

          • There are many causes of fits but most vets don’t start a dog on any AEDs (anti epilepsy drugs) unless the fits have been within six or eight weeks apart.

            The information about withdrawal of the drug states that it is not applicable:


            So one can assume that there is no withdrawal period. So, in light of that I would go against what I originally said, especially as Bob has not been on the drug for long then I would withdraw, observe carefully and see what happens.

            If he continues to have seizures then ask for a different medication. If the rear-end weakness continues then you have a separate problem and that needs attention.

          • Hi Jean, took him out this morning without pexion and he looked like a different dog. I only took him for 5 mins but that is the longest he has lasted for a long time. I am going to ask for a different medication. And just to clarify all his legs went not the rear. Thanks for your reply

          • Hi Paul.

            Sorry, I should have checked back. All his legs going sounds like the ataxia that you ge wat the start of most epilepsy medications. You are likely to get the ataxia with all of them for a couple of weeks. If you get potassium bromide (Shani has it in the form of Libromide), I would advise dividing the medicaiton between morning and afternoon and always give with food.

            I am so pleased he is more like his normal self this morning.

          • Thankyou so much! I have just googled antaxia and saw a dog on YouTube! That’s just what bob is like. I can’t believe how much help this forum has been. The annoying thing is, is that I showed my vet a video of bobs balance going and he just said that’s epilepsy! Time for a new vet!
            Again thankyou I’ve actually got a smile on my face knowing what’s wrong with my boy. And now I feel confident I will get him sorted

          • I’m so pleased that the forum has helped you. All the best with a new vet and to you and Bob too. 😊

  13. Hi, thanks for your reply. His appetite and his thirst has increased. It’s just horrible to watch him lose control of his legs

    • Paul, I would see another vet as soon as possible for a second opinion. That appetite and thirst increased is a normal reaction on Pexion, but losing control of his legs NOT! Please, go see another vet.

  14. Annoyingly my response disappeared but the back legs not working isn’t right and may need further tests being done. It’s also possible that your dog is having smaller seizures that are not as noticeable so again needs input from the vet. It might simply be that the meds aren’t right. Since the vet added Keppra I’ve been able to reduce the Pexion to 400mgs twice a day, she’s been cluster and seizure free since November, so I reduced Pexion a couple of months ago. Keppra is a human medication so a lot cheaper to purchase too. There are of course many others but it may take a while to tweak the dosage and find what’s right.

    • think we may try a different vet

      • Definitely worth a second opinion. I saw your reply to another post and would advise not to stop the medication without advice as that could bring on a seizure. It’s better to wean off whilst another is started. Please be careful.

        • Thanks again for your advice.

          • You’re welcome. Please let us know how you get in and an update on how your dogs doing? 😊

        • Get an opinion from a second vet, when you’ve got the new meds keppra is good, then start reducing the pexion.
          Good luck, if you are in Derbyshire/Nottinghamshire try Ambivets they where brilliant with my dog.

  15. My dog is 9 and has been having seizures for the 9 years. He had seizure maybe twice in 3 weeks. He was put on 3 tablets a day 100mg of pexion. But an hour after he takes the pexion he has a seizure so now he seems to b having more seizures on the medication. Can this happen with pexion

    • Yes, that can happen. Before the medication is effective you have to reckon with a couple of hours. I thought 3 or 4 hours before Pexion gets its full efficacy. Correct me if I’m wrong. So from now on, the seizure have to be much lesser then before, If not, consult your vet.

  16. Hi!
    I am the very proud owner of an extremely handsome and loving blue Staffordshire Bull terrier called Blu (original I know) we discovered he had epilepsy at about 14 weeks old! We originally treated him with phenobarbital and this totally stopped all fits but defo gave him an upset stomach and all stools where very messy and obviously where not how we all wanted the foreseeable future! So we swapped him on to the Imepitoin at advise from our vet. The stomach problems ceased! However he does fit again! Almost every other day when subjected to bright sunlight on a morning walk or general over excitement in bright light! Not bad lasting fits but his left eye closes and he raises his poor to his eye and then tenses right up for a minute or so. He knows when it is going to happen because he runs back to me immediately prior and I can see he is scarred in his eyes 🙁
    I hold him gently till it passes (30 secs-2mins) then he jumps up and goes on with his walk!! I currently give him 1.5 tablets in morn and same in the evening. Can you recommend a solution to stop him fitting altogether? I would love to stop the fits but also not destroy his organs in the process????
    Thank you

    • Jean Collinson

      Nick, there is no way to stop the fitting altogether, unless the problem is not idiopathic epilepsy and the main cause of the fits can be dealt with.

      It sounds as if Blu might have developed eilepsy after his puppy vaccinations.

      My Shani has been epileptic since she was born, as was her sister. Whilst we have good control with a mix of meds we certainly haven’t stopped the fitting altogether. She is not on Pexion, never has been.

      Di you give the pheno with food or on its own? That MAY be a way to sotp the nausea.

      I love blue Staffies.


    • I give my boy Omega 3,6,9 which I am sure really helps. He weighs 18kgs and has a 400mg of pexion twice daily. He originally started on 200mg twice daily but was still fitting and my vet increased his dose. With this dosage and the Omega he fitted twice last year. Could be worth a try and talk to your vet about increasing his dose. I buy the Omega from Treasure your Health on the net.

    • Amanda Kirkman

      Dear Nick,
      If you want to rule out physical issues you need to ask your vet to do a brain scan to see if there is a reason for the epilepsy. If it is idiopathic then I would recommend signing on the website where dog owners who have and are living with epi pets pool their information, it also helps support you. A natural diet, bachs rescue remedy and simple things like using a bag of frozen peas during fits and covering the face with a towel make a difference in lessoning the severity of the seizures. We didn’t realise until it was too late how high the temperature in the brain went during a fit which can lead to more damage. Covering the face reduces the brain activity further, and just sit at your dogs back keeping them safe in clear, quiet area. It is trial and error with epi dogs, read up all you can on natural remedies- if vet prescribes bromide use milk thistle tincture to protect the kidneys.
      Good luck, hoping you find something that works for your dog- it is so stressful and upsetting but you are not on your own and you can only do your best.
      Kind regards
      Amanda x

  17. Kayleigh Adams

    Our Labradoodle tired pexion 600mg twice daily but didnt really help, since then we have added Epiphen 90mg twice daily… we have seizures down to 3/4 weeks exactly the same as before we started the medication, however the side effects from the epiphen are getting worse… and she is weeting herself through the night… i dont know what our next step should be… any advice???

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