Potassium Bromide for Seizures
by Mollyann Holland, D.V.M., Oklahoma City, OK
Diplomate, American College of Veterinary Internal Medicine
Potassium bromide is frequently helpful in treating refractory seizures in animals. Because potassium bromide is excreted renally, it may also be preferable for use in animals that have developed hepatotoxicity while on other anticonvulsants. My compounding pharmacist prepares this as a liver flavored solution, which can easily be administered to dogs. I feel that it is important to inform my animal owners that potassium bromide solution is compounded from a reagent grade chemical, and is not a commercially available "drug."
KBr is dosed on a weight basis. Maintenance doses range from 20-100 mg/kg body weight/day, and can be given as a single or divided dose. I usually dose at 30-40mg/kg/day as a single dose with food. Due to its long half-life, KBr can take up to four months to reach steady state; therefore, a loading dose may be required if therapeutic blood levels must be reached quickly. The loading dose is 400-600 mg/kg body weight and is administered orally over 30 to 60 minutes to avoid vomiting. A loading dose is not necessary if it is possible to keep the animal on other medications (as in a case of emerging hepatotoxicity) until levels of bromide are therapeutic (0.5-1.5 mg/ml), when the other anticonvulsant can be tapered off.
Potassium Bromide Chewable "Treats" for Seizure Control
Contributed by Steve Toney, R.Ph., Erin King, C.Ph.T. and Pam Woodin, D.V.M.
Case Report: 5 y.o. male Golden Retriever with seizure disorder. The owners called our compounding pharmacy to see what we could do as they were having difficulty administering medications to their dog. We suggested medicated canine treats that we have compounded many times with a 100% success rate. The veterinarian was consulted and we prepared potassium bromide (KBr) 150 mg treats coated with liver and beef flavored powder. The owner administers two treats two times daily, and the dog now loves to take his medicine!
Note: Chewable treats can be compounded to contain a variety of medications and flavored for the specific breed or pet. This dosage form has high patient acceptance and a low risk of owner misdosing.
Potassium bromide (KBr) can be also compounded as an oral solution which is easy to flavor and convenient for use as a loading dose. However, the risk of owner misdosing is greater than with a chewie or capsule.
Phenobarbital: Problems and Solutions
While phenobarbital is often used in veterinary medicine to treat seizure disorders, there are several concerns with its use:
- there are no commercially available veterinary approved products
- phenobarbital tablets for human use are small, hard, and unscored, making them difficult to divide for individualized dosing
- phenobarbital elixir has a high alcohol content, which is problematic for cats or any species when chronically administered
- phenobarbital induces CYP450 hepatic enzymes which can result in substantial drug interactions with oral anticoagulants, steroids, antibiotics, beta-blockers, theophylline, etc.
- phenobarbital is contraindicated in dogs with hepatic disease
When you wish to prescribe phenobarbital, please be aware that our compounding pharmacy can prepare an alcohol-free, appropriately flavored oral suspension, which is highly bio-available and very easy to use when administering a loading dose or when a flexible dose is needed. Once the maintenance dose is established, the dosage form can be switched to a capsule (with a lower risk of misdosing by the owner) or a flavored chewable medicated "treat", with the added benefit of high patient acceptance.