Ask the NorthStar VETS Vet: Transitioning from phenobarbital to Keppra for seizures

Q: My chihuahua suffers from seizures and has been taking phenobarbital for the past 3 years. His last set of labs came back with significant elevation of his liver enzymes. What is the best way to transition to Keppra? Can the liver enzymes return to normal limits after discontinuing the phenobarbital?

A:Luckily, Keppra (a.k.a. leveteriacetam) is a drug that does not require a loading period to reach therapeutic levels like some other anti-seizure drugs such as phenobarbital and potassium bromide. Consequently, therapeutic benefits can be seen immediately upon dosing the drug and there is generally no need to “transition” your dog onto this drug. The dose can then sometimes also be adjusted as needed. The only downside to this drug is that it needs to be given more frequently, usually 3 times a day.

Transitioning, or weaning, him off the phenobarbital is another story. Usually, your veterinarian will start your dog on the Keppra and simultaneously lower the dose of phenobarbital and then gradually reduce it further over time. Different veterinarians follow different schedules when doing this and there’s not necessarily a right or wrong way. You should, however, only make changes in your dog’s treatment plan based on the specific recommendation of the veterinarian managing your dog’s case. They are the only ones with the necessary information (i.e. your dog’s complete history, knowledge of recent lab work, and recent physical exam findings, etc.) to be qualified to make these recommendations. If your veterinarian is unsure about how to do this, they may want to refer you to see a board certified veterinary neurologist like Dr. Melissa Logan at NorthStar VETS.

If you can indeed get him weaned off the phenobarbital, or at least reduce the dose, it is very possible that his liver values can return to normal. The liver itself is an amazing organ that can regenerate healthy cells in the face of cellular damage. It is, however, also possible that they may not as there are sometimes other conditions contributing to the these changes. Every case is different. It is also important to know that elevated liver enzymes alone do not always imply clinically significant liver disease or impaired liver function. Regardless, rechecking the blood work on a periodic basis, along with routine wellness check-ups with your family veterinarian, at least every 6-12 months, is very important in monitoring your dog’s health status, especially in cases like this. The necessary frequency of these things, again, will vary from case to case. There may also be some liver health supplements that your veterinarian could recommend as well (i.e. S-adenosyl-methionine, Marin, etc.) that may be beneficial in some cases. Again, it is very important to discuss these options with the veterinarian managing your dog’s case before making any changes in your dog’s treatment plan.

George Motley, VMD Emergency Department Supervisor

Melissa Logan, PhD, DVM, DACVIM (Neurology)

The information presented on this web site is not intended to take the place of your family veterinarian’s advice and is not intended to diagnose, treat, cure or prevent any disease. Discuss this information with your own veterinarian to determine what is right for your pet. All information is intended for your general knowledge only and is not a substitute for medical advice or treatment for specific medical conditions. We can not and do not give you medical advice via this blog. The information contained in this online site and emails is presented in summary form only and intended to provide broad understanding and knowledge. The information should not be considered complete and should not be used in place of a visit, call, consultation or advice of your veterinarian. We do not recommend the self-management of your pet’s health problems.