Comfort Pac w/ Tizanidine

In the U.S.

• Comfort Pac w/Tizanidine
• Zanaflex
• Zanaflex Capsule

Available Dosage Forms:

• Capsule
• Tablet

Therapeutic Class: Skeletal Muscle Relaxant, Centrally Acting

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 may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• Chest pain or discomfort
• fever or chills
• nausea or vomiting
• nervousness
• pain or burning while urinating
• unusual tiredness

• Blurred vision
• flu-like symptoms
• irregular heartbeat
• itching skin
• kidney stones
• right upper stomach tenderness
• seeing things that are not there
• shortness of breath
• weight gain

• Continuing vomiting
• general feeling of tiredness or weakness
• headache
• light-colored stools

Get emergency help immediately if any of the following symptoms of overdose occur:

• 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
• sleepiness or unusual drowsiness
• slow or irregular heartbeat
• sweating
• unusual tiredness or weakness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Dizziness or lightheadedness, especially when getting up from a lying or sitting position
• drowsiness
• dry mouth
• fatigue
• sleepiness
• weakness

• Constipation
• nervousness
• sore throat

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Take tizanidine exactly as it was prescribed for you. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not use this medicine in larger or smaller amounts or for longer than recommended.

In most cases you may take tizanidine up to 3 times in one day if needed. Allow 6 to 8 hours to pass between doses.

You may take tizanidine with or without food, but take it the same way each time. Switching between taking with food and taking it without food can make the medicine less effective or cause increased side effects.

Switching between tablets and capsules can also cause changes in side effects or how well the medicine works.

• Taking the tablets with food can increase your blood levels of tizanidine.

• Taking the capsules with food can decrease your blood levels of tizanidine.

Follow your doctor's instructions carefully. After making any changes in how you take tizanidine, contact your doctor if you notice any change in side effects or in how well the medicine works.

Tizanidine is a short-acting medication, and its effects will be most noticeable between 1 and 3 hours after you take it. You should take this medicine only for daily activities that require relief from muscle spasms.

Do not take more than three doses (36 mg) in a 24-hour period. Too much of this medicine can damage your liver.

You will need frequent blood tests to check your liver function.

If you stop using this medicine suddenly after long-term use, you may have withdrawal symptoms such as dizziness, fast heartbeats, tremors, and anxiety. Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture and heat.

Commonly reported side effects of tizanidine include: bradycardia, dizziness, drowsiness, hypotension, asthenia, fatigue, and xerostomia. Other side effects include: constipation, and increased liver enzymes. See below for a comprehensive list of adverse effects.

Severe renal impairment (CrCl less than 25 mL/min): Individualize therapy with lower doses during dose titration; if higher doses are required, individual doses should be increased rather increasing the dosing frequency; closely monitor for toxicity

Severe renal impairment (CrCl less than 25 mL/min): Individualize therapy with lower doses during dose titration; if higher doses are required, individual doses should be increased rather increasing the dosing frequency; closely monitor for toxicity

Administration advice:
-May take orally with or without food; however, once a formulation is decided on and a decision is made to take with or without food, this regimen should not be altered.

General:
-Because this drug has a relatively short duration of effect, dosing should occur at times when relief of spasticity is most important, such as before activities of daily living.
-Considerable variation in response has been observed and therefore careful titration is necessary in order to not exceed the dose producing the desired effect.
-Gradual dose reduction is advised on discontinuation so as to minimize risk of withdrawal and rebound hypertension, tachycardia, and hypertonia.

Monitoring:
-Obtain aminotransferase levels at baseline, 1 month after maximum dose is achieved, and as clinically indicated (e.g. if hepatic injury is suspected).
-Consider obtaining baseline renal function in elderly patients.
-Monitor for hypotension in at-risk patients and those receiving concomitant antihypertensive therapy.
-Monitor for sedation in patients receiving concomitant CNS depressant agents.

Patient advice:
-Patients may take this drug with or without food, but once the decision is made to take with or without food it should be taken this way consistently.
-Patients should check with their healthcare provider before starting or stopping any medications as this drug is known to interact with other medications.
-Patients should be advised not to abruptly stop taking this medication without first talking with their healthcare provider.
-Patients should be advised that this drug may cause hypotension and they should be careful when changing positions form lying to standing.
-Patients should be advised this drug may cause significant somnolence, especially if taken with other CNS depressants or alcohol; they should refrain from activities requiring mental alertness until the effects of the drug are known.

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

• Low blood pressure, drowsiness, dizziness, energy loss, and a dry mouth.
• Has been associated with hallucinations and rarely psychosis in approximately 3% of people.
• May not be suitable for people that rely on spasticity to sustain their posture and balance.
• May cause a drop in blood pressure when going from a sitting or lying down position to standing. This may increase the risk of falls.
• May affect a person's ability to drive or operate machinery. Alcohol should be avoided.
• May cause withdrawal symptoms such as high blood pressure and a fast heartbeat if stopped abruptly after regular extended dosing (decrease dose slowly under a doctor's advice).
• Not recommended to be taken by people with liver or kidney disease.
• Seniors may be more susceptible to the side effects of tizanidine.
• May interact with a number of other drugs including those metabolized by hepatic enzymes CYP1A2 (such as fluvoxamine, ciprofloxacin, some antiarrhythmics), and oral contraceptives. Alcohol increases the peak concentration of tizanidine and also the likelihood of side effects.
• Liver enzymes (specifically aminotransferase)should be monitored when starting treatment and for at least one month after the maximum dosage is achieved.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

The effects of tizanidine peak within 1-2 hours and start to wear off within 3 to 6 hours. Because of this short duration of effect, tizanidine may be dosed on an "as needed" basis during times when muscle spasms are at their most severe.

View as a slideshow

Safety has not been established Excreted into human milk: Unknown Excreted into animal milk: Yes Comments: If used, monitor infant for toxicity such as sedation, hypotension, and hallucinations.

As a lipid soluble drug, it might be expected to pass into breast milk.