Phenobarbitone is also known as phenobarbital and is sold under the name Epiphen.
Another anticonvulsant, primidone, is broken down in the body to make phenobarbital.
Phenobarbitone
is the most commonly used drug for prevention of seizures. It
is effective in most dogs when given twice daily – but
it is important to remember to give the drug regularly because
blood levels of the drug can drop quite quickly if a dose is
missed and this may trigger seizures.
Phenobarbitone
is usually given as tablets but a liquid form is also available.
The tablets come in a range of sizes, making it easy to give
the correct dose to a tiny dog as well as a giant one! The drug
is broken down in the liver and so with long-term use it may
have some effects on the liver. If your dog is prescribed phenobarbital
your vet will want to take regular blood tests to check that
there is no damage to your dog’s liver.
It
is very important when using phenobarbital that the blood levels
of the drug are kept at an appropriate level. If levels get too
high the drug can have more severe toxic effects, and if they
are too low there may be no beneficial effect from the drug.
There is a blood test to measure levels of phenobarbital in
the blood and if your vet has prescribed phenobarbital for your
dog he will want to monitor blood samples. These tests may be
done several times in the early weeks of treatment to help determine
the correct dose of drug for your dog, and then on a less frequent
basis to monitor long-term effects.
All
drugs have side-effects and phenobarbital is no exception. Usually
these are relatively mild and may wear off once your dog gets
used to the drug. Drowsiness, increased appetite and thirst are
common. Most vets will use phenobarbital in all dogs with epilepsy
unless there is a reason not to do so. Dogs with liver disease
may have problems with the drug and so alternative treatment
may be better in these cases. For some dogs phenobarbital alone
is not enough to control seizures sufficiently and a second drug
may need to be added to their regime.