Seizure Medications for Dogs

Phenobarbital

One of the most commonly used medications to manage seizures in dogs is called phenobarbital. It is a type of drug called a barbiturate and works like other seizure medications by sedating or slowing brain activity. This slowing of the brain activity is helpful since the brain is overactive when a dog is having a seizure. Phenobarbital is commonly used because it is not only effective but it is also usually one of the least expensive options for seizure medication. Medications to manage seizures are typically used life long so the cost of them adds up quickly.

If your pet takes phenobarbital then your veterinarian will routinely check its blood work to ensure there are no detrimental side effects and that the drug levels are appropriate in the body. Phenobarbital is known to cause liver dysfunction since it is primarily metabolized in the liver so some pets may not be able to take it if their livers are already compromised or damaged. It is typically dosed twice daily.

Levetiracetam

Much newer to the seizure medication market than phenobarbital, levetiracetam is a drug more often known by its brand name, Keppra®. Instead of being metabolized by the liver, levetiracetam is metabolized by the kidneys so it may be a better option than phenobarbital for some pets.

Levetiracetam is usually dosed three times a day but there is also an extended release product that allows for twice daily dosing. There are no drug level monitoring blood work options specific to this drug like there are for phenobarbital but routine organ function screening is still recommended for most dogs on any long term medication.

Potassium Bromide

Potassium bromide, or KBr, is a medication used to help manage seizures in dogs. It may come in a tablet, capsule, or liquid form. Potassium bromide may be used alone or in addition to another seizure medication, most commonly phenobarbital, depending on the severity of your dog's seizures. Blood monitoring is typically performed a few times a year to monitor the level of this drug in your dog's body. Sedation is the most commonly observed side effect in dogs taking this medication but that usually goes away on its own as a dog's body adjusts to the KBr.

Diazepam or Midazolam

Diazepam and midazolam are drugs in the benzodiazepine class. They are short-acting and cause sedation so they are typically only used when a dog is actually having seizures, not as a long term, daily medication to help manage them. These medications are usually also only used as injections but may be sent home to use rectally in a dog that is having a seizure at home. While they are short-acting, they are also very fast-acting so this means they take effect quickly but don't last very long in the body.

Zonisamide

While no one really understands exactly how zonisamide works, it is a newer medication that may be used to help manage seizures in dogs. Zonisamide can be used alone or in addition to another medication. It is also typically given twice daily in a pill form. Side effects are not common but some reports of wobbling and sedation have been noted.