What is tizanidine?

Tizanidine is a short-acting muscle relaxer. It works by blocking nerve impulses (pain sensations) that are sent to your brain.

Tizanidine is used to treat spasticity by temporarily relaxing muscle tone.

Tizanidine may also be used for purposes other than those listed in this medication guide.

Precautions

Do not use this medication if you are allergic to tizanidine, or if you are also taking the antidepressant fluvoxamine (Luvox), or the antibiotic ciprofloxacin (Cipro).

Before using tizanidine, tell your doctor if you are allergic to any drugs, or if you have:

  • liver disease;
  • kidney disease;
  • high or low blood pressure; or
  • a history of "Long QT syndrome."

If you have any of these conditions, you may not be able to use tizanidine, or you may need a dosage adjustment or special tests during treatment.

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether tizanidine passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

In older adults, tizanidine may take much longer to clear from the body. Follow your doctor’s instructions about your specific dosage and medication schedule.

Tizanidine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Dizziness is most likely to occur when you rise from a sitting or lying position. Get up slowly to prevent dizziness and a possible fall.

Do not use tizanidine at a time when muscle tone is needed to assure safe balance and movement for certain activities. In some situations, it may endanger your physical safety to be in a state of reduced muscle tone.

Cold or allergy medicine, narcotic pain medicine, sleeping pills, other muscle relaxers, and medicine for seizures, depression or anxiety can add to sleepiness caused by tizanidine. Tell your doctor if you need to use any of these other medicines together with tizanidine.

Avoid drinking alcohol. It can increase some of the side effects of tizanidine.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include drowsiness, confusion, slow heart rate, shallow breathing, feeling light-headed, fainting, or coma.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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Side Effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • feeling light-headed, fainting, slow heart rate;
  • hallucinations, confusion, unusual thoughts or behavior;
  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
  • burning or pain when you urinate.

Less serious side effects may be more likely to occur, such as:

  • drowsiness or dizziness;
  • feeling anxious or nervous;
  • numbness or tingling;
  • stomach pain, diarrhea, constipation, vomiting;
  • fever;
  • dry mouth;
  • muscle weakness, back pain;
  • increased muscle tone or spasms; or
  • sweating or skin rash.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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Interactions

Before taking tizanidine, tell your doctor if you are using any of the following drugs:

  • acyclovir (Zovirax);
  • cimetidine (Tagamet);
  • famotidine (Pepcid);
  • ticlopidine (Ticlid),
  • zileuton (Zyflo);
  • birth control pills;
  • antibiotics such as enoxacin (Penetrex), gatifloxacin (Tequin), levofloxacin (Levaquin), lomefloxacin (Maxaquin), moxifloxacin (Avelox), ofloxacin (Floxin), sparfloxacin (Zagam), trovafloxacin (Trovan), or norfloxacin (Noroxin);
  • blood pressure medications such as clonidine (Catapres), guanabenz (Wytensin), guanfacine (Tenex), or methyldopa (Aldomet); or
  • heart rhythm medications such as amiodarone (Cordarone, Pacerone), mexiletine (Mexitil), propafenone (Rhythmol), and verapamil (Calan, Covera, Isoptin).

This list is not complete and there may be other drugs that can interact with tizanidine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Other Names

Zanaflex and tizanidine

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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