Tizanidine

Tizanidine (ZANAFLEX) 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.

Common uses

Tizanidine is used to help relax certain muscles in your body. It relieves the spasms, cramping, and tightness of muscles caused by medical problems such as multiple sclerosis or certain injuries to the spine. Tizanidine does not cure these problems, but it may allow other treatment, such as physical therapy, to be more helpful in improving your condition.
Tizanidine acts on the central nervous system (CNS) to produce its muscle relaxant effects. Its actions on the CNS may also cause some of the medicine's side effects.
This medicine is available only with your doctor's prescription.

Before using

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.

Directions

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
Your doctor may occasionally change your dose to make sure you get the best results from this medication.
Take this medication with a full glass of water.
Tizanidine is a short-acting medication, and its effects will be most noticeable between 1 and 6 hours after you take it. This medication should be taken only for daily activities that require relief from muscle spasticity.
In most cases, you may take up to three doses in one day if needed. Allow 6 to 8 hours to pass between doses.
Carefully follow your doctor's instructions about taking this medication with or without food. Taking tizanidine tablets with food can increase the levels of tizanidine in your blood stream, but taking tizanidine capsules with food can decrease the levels.

Cautions

Clinical experience with long-term use of tizanidine at doses of 8 to 16 mg single doses or total daily doses of 24 to 36 mg is limited. In safety studies, approximately 75 patients have been exposed to individual doses of 12 mg or more for at least one year or more and approximately 80 patients have been exposed to total daily doses of 30 to 36 mg/day for at least one year or more. There is essentially no long-term experience with single, daytime doses of 16 mg. Because long-term clinical study experience at high doses is limited, only those adverse events with a relatively high incidence are likely to have been identified.


Possible side effects

Tizanidine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
• dizziness
• drowsiness
• weakness
• nervousness
• depression
• vomiting
• tingling sensation in the arms, legs, hands, and feet
• dry mouth
• constipation
• diarrhea
• stomach pain
• heartburn
• increased muscle spasms
• back pain
• rash
• sweating
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:
• nausea
• extreme tiredness
• unusual bleeding or bruising
• lack of energy
• loss of appetite
• pain in the upper right part of the stomach
• yellowing of the skin or eyes
• unexplained flu-like symptoms
• seeing things or hearing voices that do not exist
• slow heartbeat
• changes in vision
Tizanidine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you take too much

Symptoms of overdose may include:
• drowsiness
• extreme tiredness
• confusion
• slow heartbeat
• fainting
• dizziness
• slow or shallow breathing
• loss of consciousness

Additional information

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.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Drug 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.
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.