TIZANIDINE (Systemic)?

Some commonly used brand names are:

In the U.S.?

• Zanaflex

? Not commercially available in Canada.

Category

• Antispastic

Description

Tizanidine (tye-ZAN-i-dine) is used to help relax certain muscles inyour body. It relieves the spasms, cramping, and tightness of muscles causedby medical problems such as multiple sclerosis or certain injuries to thespine. 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 musclerelaxant effects. Its actions on the CNS may also cause some of the medicine'sside effects.

This medicine is available only with your doctor's prescription, in thefollowing dosage form:

Oral
• Capsules (U.S.)
• Tablets (U.S.)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For tizanidine, thefollowing should be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to tizanidine. Also tell your health care professional ifyou are allergic to any other substances, such as foods, preservatives, ordyes.

Pregnancy?Tizanidine has not been studied in pregnant women.However, studies in animals have shown that tizanidine causes birth defectsand other pregnancy problems. Before taking this medicine, make sure yourdoctor knows if you are pregnant or if you become pregnant.

Breast-feeding?Tizanidine may pass into the breast milk. However,this medicine has not been reported to cause problems in nursing babies.

Children?Studies on this medicine have been done only in adultpatients, and there is no specific information comparing use of tizanidinein children with use in other age groups.

Older adults?Studies in older adults show that tizanidine staysin the body a little longer than it does in younger adults. Your doctor willconsider this when deciding on your dose.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingtizanidine, it is especially important that your health care professionalknow if you are taking any of the following:

• Antihypertensives (high blood pressure medicine)?Severe lowblood pressure may occur

• Fluvoxamine (e.g., Luvox)?This medicine should not be usedwith tizanidine. It can cause increased blood levels of tizanidine and lowblood pressure.

• Oral contraceptives (birth control pills)?The chance of sideeffects may be increased

• Phenytoin?Tizanidine may increase the blood levels of phenytoin,which increases the chance of serious side effects

Other medical problems?The presence of other medicalproblems may affect the use of tizanidine. Make sure you tell your doctorif you have any other medical problems, especially:

• Kidney disease or
• Liver disease?The chance of side effects may be increased;higher blood levels of tizanidine may result and a smaller dose may be needed

Proper Use of This Medicine

When youtake the different dosage forms (tablets, capsules, capsule contents sprinkledover applesauce) of tizanidine with food, it effects the amount of the medicineabsorbed into your blood differently. Follow your doctor's instructions forwhen to take this medicine and whether or not you should take it with food.

Take this medicine only as directed. Do not take more of it and do nottake it more often than recommended on the label, unless otherwise directedby your doctor. To do so may increase the chance of side effects.

Dosing?The dose of tizanidine will be different fordifferent patients. Follow your doctor's orders or thedirections on the label. The following information includes only theaverage doses of tizanidine. If your dose is different,do not change it unless your doctor tells you to do so.

• For oral dosage form (capsules and tablets):
  • For muscle relaxation:
    • Adults?The dose is 8 milligrams (mg) every six to eight hoursas needed. No more than 36 mg should be taken within a twenty-four-hour period.
    • Children?Use and dose must be determined by your doctor.

Missed dose?If you miss a dose of this medicine, and you rememberwithin an hour or so of the missed dose, take it as soon as you remember.However, if you do not remember until later, skip the missed dose and go backto your regular dosing schedule. Do not double doses.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

Yourdoctor should check your progress at regular visits, especially during thefirst few weeks of treatment with this medicine. During this time the amountof medicine you are taking may have to be changed often to meet your individualneeds.

Do not suddenly stop taking this medicine. Unwantedeffects may occur if the medicine is stopped suddenly. Check with your doctorfor the best way to reduce gradually the amount you are taking before stoppingcompletely.

This medicine will add to the effects of alcohol and other CNS depressants(medicines that make you drowsy or less alert). Some examples of CNS depressantsare antihistamines or medicine for hay fever, other allergies, or colds; sedatives,tranquilizers, or sleeping medicine; prescription pain medicine or narcotics;barbiturates; medicine for seizures; other muscle relaxants; or anesthetics,including some dental anesthetics. Check with your doctorbefore taking any of the above while you are using tizanidine.

This medicine may cause dizziness, drowsiness, lightheadedness, clumsinessor unsteadiness, or vision problems in some people. Make sure you know how you react to this medicine before you drive, use machines,or do anything else that could be dangerous if you are not alert, well-coordinated,and able to see well.

Tizanidine may cause dryness of the mouth. For temporary relief, use sugarlesscandy or gum, melt bits of ice in your mouth, or use a saliva substitute.However, if dry mouth continues for more than 2 weeks, check with your medicaldoctor or dentist. Continuing dryness of the mouth may increase the chanceof dental disease, including tooth decay, gum disease, and fungus infections.

Dizziness, lightheadedness, or fainting may occur whenyou get up suddenly from a lying or sitting position. Getting up slowly mayhelp lessen this problem.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects.Although not all of these side effects may occur, if they do occur they mayneed medical attention.

Check with your doctor as soon as possibleif any of the following side effects occur:

More common

Chest pain or discomfort; fever; loss of appetite; lower back or sidepain; nausea and/or vomiting; nervousness; pain or burning while urinating; painful or difficult urination; soreson the skin; tingling, burning, or prickling sensations; unusual tiredness; yelloweyes or skin

Less common

Black, tarry stools; bloody vomit; blurred vision; chills or sore throat; coldness; convulsions(seizures); cough or hoarseness; dark urine; dry, puffy skin; eye pain; fainting; influenza(flu)-like symptoms; irregular heartbeat; kidney stones; persistent anorexia; pruritus; right upper quadrant tenderness; seeing things that are not there; shortness of breath; slow or irregularheartbeat; unusual tiredness or weakness; weight gain

Incidence not known

Continuing vomiting; general feelingof tiredness or weakness; headache; light-colored stools

Get emergency helpimmediately if any of the following symptoms of overdose occur

Symptoms of overdose

Blurred vision; change in consciousness; chest pain or discomfort; confusion; decreased awareness or responsiveness; difficult or troubled breathing; dizziness, faintness or lightheadedness when getting up from a lying position; irregular, fast or slow, or shallow breathing; lightheadedness, dizziness or fainting; loss of consciousness; pale or blue lips, fingernails,or skin; severe sleepiness; shortness of breath; sleepiness or unusual drowsiness; slow or irregular heartbeat; sweating; unusual tiredness or weakness

Other sideeffects may occur that usually do not need medical attention. These side effectsmay go away during treatment as your body adjusts to the medicine. However,check with your doctor if any of the following side effects continue or arebothersome:

More common

Anxiety; back pain; constipation; depression; diarrhea; difficulty in speaking; dizziness or lightheadedness, especially when getting up from a lying orsitting position; drowsiness; dry mouth; heartburn; increasedsweating; increased muscle spasms or tone; muscle weakness; pain or burning inthroat; runny nose; skinrash; sleepiness; stomachpain; uncontrolled movements of the body

Less common

Difficulty swallowing; dry skin; general feeling of discomfort or illness; increased need to urinate; joint or muscle pain orstiffness; loss of hair; migraine headache; mood changes; neck pain; passing urine more often; shivering; swelling of feet or lowerlegs; swollen area that feels warm and tender; trembling or shaking; trouble sleeping; unusual feeling of well-being; unusual tiredness or weakness; weight loss

Other side effects not listed abovemay also occur in some patients. If you notice any other effects, check withyour doctor.