Valeant’s Mysoline® (primidone) 250 mg Tablet Design Changes

Due to manufacturing changes, Mysoline 250 mg tablets are changing in appearance. Other dosages of Mysoline (such as the 50 mg tablets) have not changed. The new version of Mysoline is FDA-approved and bioequivalent to the older version of Mysoline. It still has the same amount of the active ingredient primidone as the previous version, although its inactive ingredients vary from the current tablet. Because the tablet is essentially the same medicine as before, your insurance coverage should not change.

If patients have any questions regarding this change, they should speak with their pharmacist and/or health care provider. Above all, people with epilepsy and/or seizure disorders should not change their medication or stop taking it without consulting their health care providers.

Answers to Frequently Asked Questions Regarding the Mysoline® (primidone) 250 mg Change in Tablet Design

The new Mysoline 250 mg tablet is a round-white tablet that contains the same 250 mg of the active ingredient (primidone) as the previous tablet version and is considered bioequivalent to the previous tablet version. The two tablets do differ slightly in their inactive ingredients.

Valeant does not directly manufacture all of its pharmaceutical products – our previous manufacturing site was unable to continue to manufacture the previous version of Mysoline 250 mg tablets so Valeant needed to qualify another manufacturing site to continue to produce the product.  This new site (Watson) and version of the product has now been FDA approved, and the new Mysoline 250 mg tablet is considered bioequivalent to the previous version.

Valeant is currently working to qualify an additional manufacturing site that will have the capability to produce Mysoline 250 mg tablets using the previous formulation and tablet design. The company is working to validate this site and manufacturing process with FDA as quickly as possible, but are unable to provide a firm date as to when this will take place.  If you would like to be notified if and when the yellow-square version of Mysoline 250 mg tablets becomes available, please contact Valeant at 800-556-1937 to have your name and contact information added to their notification list.

Valeant received FDA approval to market this new tablet design on June 13th, 2008, and we began shipping quantities of the product out to wholesalers on Monday, June 16th. We expect that Mysoline 250 mg tablets should be available through your local pharmacy just as quickly as your pharmacy can order it from their wholesaler or distributor.

This new tablet design maintains the same NDC number as the previous Mysoline 250 mg tablet 100 count bottle, so your insurance coverage should not change.

There are multiple manufacturers on the market for generic primidone 250 mg tablets. Additionally, the current manufacturing changes affect the Mysoline 250 mg tablets only, and inventory of Mysoline 50 mg tablets from our previous manufacturing site is readily available, and unaffected by the changes outlined above. As is customary, when any changes occur with anticonvulsant therapy, we suggest that patients receive additional counseling from their physician.