Mysoline (MY-soh-leen) is the brand name used in the United States, Canada, and many other countries for the seizure medicine with the generic name primidone (PRIM-ih-dohn).

Mysoline was introduced for epilepsy in the 1950s. It remains a well-known medication but it is used by only a small percentage of people with epilepsy. Although it is very effective, side effects limit its value.

Forms
Mysoline is manufactured in the United States by Valeant Pharmaceuticals. The name or appearance may differ in other places. The dose (measured in milligrams, abbreviated "mg") will usually be the same. These descriptions apply to the U.S. versions:

Tablets

		50-mg white, square-shaped tablet embossed with "M" and "Mysoline 50"
		250-mgyellow, square-shaped tablet embossed with "M" and "Mysoline 250"

Generic primidone made by other companies is also available in the United States, in the same doses.

Both sizes of Mysoline tablets are scored so they can be cut in half easily if 125 mg is prescribed.

In Canada, primidone is available in 125-mg chewable tablets (Apo-Primidone) (not shown).

How to take and store Mysoline
Swallow each tablet whole. Don't bite or chew it.

Mysoline can be taken either with food or without food, but it's important to be consistent day in and day out. People who usually take Mysoline with food should try to do that all the time, because it affects the way the medicine is used by the body.

Be careful if the doctor writes a new prescription using a different kind of pill. For example, if you've been using 50-mg tablets and the new prescription is for 250-mg tablets, be careful to use the correct number. Don't automatically continue to use the same number of pills as before.

Store Mysoline tablets at room temperature, away from light and moisture and out of the reach of children.

What if I forget?
A forgotten dose should be taken right away. If it is almost time for the next dose, just use one dose, not a double dose, and call the doctor's office for more advice.

Do your best to follow the doctor's directions. If you forget doses often, it may be a good idea to get a special pillbox or watch with an alarm to remind you.

Taking the right amount of seizure medicine on time every single day is the most important step in preventing seizures!

Reviewed June 2008 by Steven C. Schachter, MD, epilepsy.com Editorial Board.