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Zanaflex (tizanidine hydrochloride) Tablets and Capsules - Changes to the Contraindications and Warnings Sections of the Approved Product Labeling

MedWatch - The FDA Safety Information and Adverse Event Reporting Program

ROCKVILLE, Md., April 11, 2007--Acorda Therapeutics and FDA informed healthcare professionals of changes to the CONTRAINDICATIONS and WARNINGS Sections of the product labeling for Zanaflex, a drug used to treat spasticity, In pharmacokinetic studies where tizanidine was coadministered with either fluvoxamine or ciprofloxacin (CYP1A2 inhibitors), the serum concentration of tizanidine was significantly increased and potentiated its hypotensive and sedative effects. Although there are no clinical studies evaluating the effects of other CYP1A2 inhibitors on tizanidine, coadministration of tizanidine with other CYP1A2 inhibitors (zileuton, other fluroquinolones, antiarrythmics, cimetidine, famotidine, oral contraceptives, acyclovir and ticlopidine) should be avoided.

A portion of the Dear Healthcare letter is below. Please see the attachment for the complete letter.

March 27,2007

Russell Katz, M.D., Director

Division of Neurology Products (DM)

Food and Drug Administration

Center of Drug Evaluation and Research

5901-B Ammendale Road

Beltsville, MD 20705-1266

Re: Zanaflex CapsulesTM(t izanidine hydrochloride)

NDA 21-447


Dear Dr. Katz,

Reference is made to the February 5,2007 email in which the content of the Dear Healthcare Provider letter was approved for Zanaflex capsule (tizanidine hydrochloride) NDA 21-447. Acorda Therapeutics (Acorda) is now providing a final approved copy of a "Dear Health Care Professional" to the Division as Attachment 1.

The letter will he sent to physicians who have prescribed iizanidine hydrochloride, and pharmacists who have ordered tizanidine hydrochloride, Zanaflex Capsules and Zanaflex Tablets. This list includes approximately 75,000 physicians and 43,000 pharmacists.

The approval letter includes Zanaflex tablets by cross reference to NDA 20-397 for Zanaflex (tizanidine hydrochloride) Tablets for the combined package insert.

A copy of the Dear Healthcare Provider letter was also provided to DDMAC under FDA FORM 2253.

If you have any questions or comments regarding this submission, please contact me at (914) 347-4300, ext 139.

Brian A. Walter, Ph.D.
Senior Director Regulatory Affairs
And Quality Assurance

Call 1-800-FDA-1088 (1-800-332-1088)

Posted: April 2007