Tizanidine (patient information)

IMPORTANT WARNING:

[Posted 04/11/2007] Acorda Therapeutics and FDA informed healthcare professionals of changes to the CONTRAINDICATIONS and WARNINGS Sections of the product labeling for tizanidine (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. For more information visit the FDA website at: http://www.fda.gov/medwatch/safety/2007/safety07.htm#Zanaflex, http://www.fda.gov/medwatch/safety/2007/Zanaflex_DHCP_3-27-2007.pdf and http://www.fda.gov/medwatch/safety/2007/Zanaflex_PI_apr07.pdf.

Why is this medication prescribed

Tizanidine, a muscle relaxant, is used to help relax certain muscles in your body. It relieves the spasms and increased muscle tone caused by medical problems such as multiple sclerosis or spinal injury.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used

Tizanidine comes as a tablet to take by mouth. It usually is taken two or three times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tizanidine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

What special precautions should I follow

Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

Before taking tizanidine

• tell your doctor and pharmacist if you are allergic to tizanidine or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, including other medications that cause drowsiness, medications for high blood pressure, oral contraceptives, and vitamins.
• tell your doctor if you have or have ever had kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking tizanidine, call your doctor immediately.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking tizanidine.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
• remember that alcohol can add to the drowsiness caused by this drug.

What should I do if I forget a dose

If you take several doses per day, take the missed dose as soon as you remember it and take any remaining doses for that day at evenly spaced intervals. However, if you remember a missed dose when it is almost time for your next scheduled dose, skip the missed dose. Do not take a double dose to make up for a missed one.

Side Effects

Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

Minor Side Effects

Side effects from tizanidine can occur. Tell your doctor if any of these symptoms are severe or do not go away:

• dizziness
• upset stomach
• vomiting
• tingling sensation in the arms, legs, hands, and feet
• dry mouth
• increased muscle spasms

Severe Side Effects

If you experience either of the following symptoms, call your doctor immediately:

• yellowing of the skin or eyes
• unexplained flu-like symptoms

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know

Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to tizanidine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Zanaflex®