Medically reviewed by Drugs.com. Last updated on Oct 22, 2021.
Commonly used brand name(s)
In the U.S.
- Comfort Pac w/Tizanidine
- Zanaflex Capsule
Available Dosage Forms:
Therapeutic Class: Skeletal Muscle Relaxant, Centrally Acting
Uses for Zanaflex
Tizanidine is used to help relax certain muscles in your body. It relieves spasms, cramping, and tightness of the 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 Zanaflex
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of tizanidine in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of tizanidine in the elderly. However, elderly patients are more likely to have kidney problems, which may require caution in patients receiving this medicine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Potassium Citrate
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Calcium Oxybate
- Estradiol Valerate
- Ethinyl Estradiol
- Ethynodiol Diacetate
- Gabapentin Enacarbil
- Glycopyrronium Tosylate
- Magnesium Oxybate
- Morphine Sulfate Liposome
- Peginterferon Alfa-2b
- Potassium Oxybate
- Ropeginterferon Alfa-2b-njft
- Secretin Human
- Sodium Oxybate
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of Zanaflex
This section provides information on the proper use of a number of products that contain tizanidine. It may not be specific to Zanaflex. Please read with care.
Take this medicine only as directed by your doctor. Do not take more of it and do not take it more often than your doctor ordered. To do so may increase the chance of side effects.
When you take the different dosage forms (tablets, capsules, capsule contents sprinkled over applesauce) of tizanidine with food, it affects the amount of the medicine absorbed into your blood differently. Follow your doctor's instructions for when to take this medicine and whether or not you should take it with food.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage forms (capsules or tablets):
- For muscle relaxation:
- Adults—At first, 2 milligrams (mg) every 6 to 8 hours. Your doctor may adjust your dose as needed. Do not take more than 36 mg within a 24-hour period.
- Children—Use and dose must be determined by your doctor.
- For muscle relaxation:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using Zanaflex
It is important that your doctor check your progress at regular visits, especially during the first few weeks of treatment with this medicine. This will allow your doctor to see if the medicine is working properly and to check for unwanted effects. Blood tests may be needed to check for unwanted effects.
Do not use this medicine together with ciprofloxacin or fluvoxamine. Using these medicines together may cause serious unwanted effects.
Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem.
Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.
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 depressants are 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 doctor before taking any of the above while you are using tizanidine.
This medicine may cause dizziness, drowsiness, lightheadedness, clumsiness or 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.
Hallucinations (visual) may occur while you are using this medicine. Check with your doctor right away if you have hallucinations (seeing things that are not there).
This medicine may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.
Do not suddenly stop taking this medicine without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping completely. This may help prevent a possible worsening of your condition and reduce the possibility of withdrawal symptoms.
Tizanidine may cause dryness of the mouth. For temporary relief, use sugarless candy 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 medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
Zanaflex side effects
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
- 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
Incidence not known
- Continuing vomiting
- general feeling of tiredness or weakness
- light-colored stools
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Blurred vision
- change in consciousness
- chest pain or discomfort
- 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
- 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
- dry mouth
- 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.
More about Zanaflex (tizanidine)
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- Drug class: skeletal muscle relaxants
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