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Pexion 400mg
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  • 1Get a prescription from your vet
  • 2Place your order with Pet Drugs Online
  • 3Attach a prescription and tell us about your pet, read more
  • 4Our vets will double check your order
  • 5Your order is dispatched right away
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Pexion 400mg

This item requires a vet's prescription

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  • Vet price £1.18
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Prescription Info.
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Pexion 400mg

Pexion 400mg is for the treatment of primary epilepsy in dogs.

 It is a white, oblong tablet supplied in 100 and 400mg tablets, either individually or in packs of 100. (100mg tablets can also be found on our website).

Pexion is used for the reduction of the frequency of generalised seizures, due to idiopathic epilepsy in dogs. This medication is to be used after careful evaluation of alternative treatment options.

Pexion is a prescription item and will be sent once a valid prescription is received. Please follow the instructions given by your vet.

How does Pexion work? Pexion acts on a specific receptor in the brain cells to help reduce the amount of excessive electrical activity. Therefore, like other epilepsy medications, it reduces the amount of seizures your dog has.

The medication is intended to be administered twice daily (12 hours apart) and the dose depends on the weight of your dog:

5kg - 1/2 x 100mg tablet

5kg to 10kg - 1 x 100mg tablet

10kg to 15kg - 1 & 1/2 x 100mg tablet

15kg to 20kg - 1/2 x 400mg tablet

20kg to 40kg - 1 x 400mg tablet

40kg to 60kg - 1 & 1/2 x 400mg tablet

Over 60kg - 2 x 400mg tablet

How long does Pexion take to work? Pexion starts to work within a few hours. It will take a little while before any improvements are noticed in regards to the dog's seizure patterns. This may be because your dog only experiences seizures every few weeks or it can take a short time for your Vet to find the correct dose for your dog.

Do not use Pexion in dogs with severely impaired hepatic functions, severe renal or cardiovascular disorders.

Once the packet is open, the product's shelf life is 8 months.

This is a prescription item and will be sent once a valid prescription is received.

To check the most up to date information about this product, please read its Summary of Product Characteristics (SPC) on the Veterinary Medical Directorate’s (VMD) Product Information Database:

View summary of product characteristics (SPC)

For orders over £29 postage is free. For orders under £29 we charge £2.99 for postage

For Light items (under 2kg) our standard method is Royal Mail Second Class (there are a few exceptions, so if in doubt check our Delivery page).

To get it faster you can upgrade Light items to Royal Mail 1st Class or a Guaranteed Next Day Courier service, Saturday Courier or even before 12 noon services. There's a small fee, but if you're in a hurry they are worth considering. To qualify for next working day delivery, orders must be placed before 12 Noon Monday to Thursday. There is no standard Saturday courier delivery.

Heavy items weighing 2kg and more are sent via courier. If ordered before noon Monday to Thursday, Heavy items will be delivered next working day. Heavy items ordered after 12 Noon Friday, or anytime Saturday and Sunday will dispatched on Monday for a Tuesday delivery.

Please note that if you are purchasing a mix of Light and Heavy items at the same time, these will be sent separately. The Heavy items being sent by Courier, the Light items by Royal Mail Second Class.

All exceptions to these guidelines are noted in the product description.
For more information, view our Delivery page.

If you see the "prescription required" sign next to an item you’d like to order, it means the item can only be issued with a prescription. While you can add these items to your shopping cart and pay for them along with other non-prescription products, we can’t dispatch them until we’ve received a prescription.

Product reviews for prescription products are not allowed by the RCVS. But here is what our customers say about our service:

Service reviews have been compiled from 38002 customer reviews


Very easy to use and speedy delivery.


Quick,efficient service. Fair price. Would definitely use them again!


Great price and super fast delivery. Great website and easy to use


The delivery on my items is very fast always good service


I have been using Pet Drugs Online for the last few years. Their medication is always the cheapest I've found, saving me thousands of pounds it would have cost me buying it from the vets. Excellent customer service and delivery as well.


Good service & great value, their savings are a lot more than other online pet drug companies .
Delivery could've been quicker considering it wasn't free.

On 23 Mar 2018 Pet Drugs Online responded:
Thankyou for your feedback. The effipro treatment is a fipronil based treatment which a large number of flea products use. These are effective in killing adult fleas but not the egg or larvae stage. It would be worth either trying frontline plus which will treat all stages of the flea cycle. Or use a household spray to treat the immature stages that are in the home
Kind regards Shirley 


Good value for money and quick service


Fantastic prices, well packaged, arrived quickly. Recommend to everyone I meet!


Quick delivery. Well packaged. Good prices.


Excellent service and good value

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