If your pet has been prescribed something called phenobarbital, you might want a bit more information on what this drug is and how it will help your pet. Read on to find out more!

What is phenobarbital? 

Phenobarbital, marketed in the UK under a number of brand names, is an anti-epileptic drug, licensed for use in dogs. It is sometimes also used in cats, off-licence on the Cascade. This means it helps to control seizures. A seizure is an episode of uncontrolled electrical activity in the brain that can cause twitching, convulsions, loss of awareness and hypersalivation. Phenobarbital works to keep this electrical activity under control. It is the most commonly used drug for seizures and has proven its effectiveness.

It normally takes 1-2 weeks to get to appropriate levels in the bloodstream, therefore it can take that long before any improvements are seen. However, once these levels are achieved, these levels are easily maintained provided the drug is given regularly, as recommended.

Why would my animal need phenobarbital?

This is a first-line drug for animal’s experiencing regular seizures, that are caused by epilepsy. Seizures may be caused by other conditions as well (including liver dysfunction, brain cancer, brain bleeds and ingestion of poisons), but these should have been ruled out prior to starting medication. It can help to control both the number and severity of seizures. It is important to remember that your animal may still experience seizures despite being on the medication, but they will be massively reduced in comparison.

How is it given? 

Phenobarbital can either be given in tablet or liquid form. There are different strengths of tablet, which one is given is decided by your animal’s weight. Normally animals under 12kg would be given the liquid form. 

It is normally administered twice daily. If you miss a dose, it is important you don’t double up next time. Instead, give the normal dose at the next scheduled time.

Are there any side effects?

Common side effects include: 

  • Drinking more 
  • Urinating more 
  • Ataxia (wobbliness)
  • Sleepiness/sedation
  • Liver dysfunction 
  • Bone marrow dysfunction

If you have any concerns that your animal is experiencing these symptoms, seek advice from your vet immediately.

Vetster option 01 (Blog)

Will my dog always need to take this drug?

It will take 1-2 weeks for the drug to reach optimum levels in the drug, therefore you may not see any improvement in your pet’s condition till then

It is likely that once your pet has started taking this medication that they will stay on it for a long time. However, it is important that the levels of the drug found in the blood are monitored over time. This is done via a blood test. It is generally recommended to do this: 

  • 2 weeks after the drug is started
  • 3 months after starting 
  • 6 months after starting
  • Every 6 months after this. 
  • 2 weeks after making a change to the dose

A change in dose may be required if your animal is experiencing any side effects, or if you notice that the frequency or severity of your animal’s seizures are increasing. Blood tests are also important due to the negative impact phenobarbital can have on the liver, therefore parameters that tell us about the liver’s health and functionality need to be carefully monitored.

It is important not to abruptly stop giving this drug. If your vet decides it is no longer an appropriate treatment for your pet, they should be slowly weaned off it. 

Where can I get phenobarbital from? 

You can either get phenobarbital through your practice, or you can purchase it from an online pharmacy, but you will require a written prescription from your vet prior to doing this. It is a Schedule 3 Controlled Drug, therefore there are strict limitations on the amount of medication your vet will be able to dispense at a time. 

It is also important to remember that it is illegal under the Misuse of Drugs legislation to hold this drug without a valid prescription. In addition, it is illegal to substitute a human version of the drug for a prescribed veterinary brand.

In addition, any supply of phenobarbital you have in your home should be kept locked safely away.

Can any animals not have phenobarbital? 

Phenobarbital should not be prescribed to pregnant animals or animals with impaired liver function. 

In conclusion…

Phenobarbital is very commonly used and successful in managing epileptic seizures, but will not cure the condition completely. If you still have any concerns, or are worried that your animal needs further medical attention, please seek advice from your veterinarian.

You might also be interested in: