Tizanidine (Zanaflex): Uses & Side Effects (2024)

What is this medication?

TIZANIDINE (tye ZAN i deen) treats muscle spasms. It works by relaxing your muscles, which reduces muscle stiffness. It belongs to a group of medications called muscle relaxants.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Zanaflex

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Kidney disease
• Liver disease
• Low blood pressure
• Mental health disease
• An unusual or allergic reaction to tizanidine, other medications, foods, dyes, or preservatives
• Pregnant or trying to get pregnant
• Breast-feeding

How should I use this medication?

Take this medication by mouth with water. Take it as directed on the prescription label. You can take it with or without food. You should always take it the same way. Keep taking this medication unless your care team tells you to stop. Stopping it too quickly can cause serious side effects.

Talk to your care team about the use of this medication in children. Special care may be needed.

Patients over 65 years of age may have a stronger reaction and need a smaller dose.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

• Ciprofloxacin
• Fluvoxamine
• Narcotic medications for cough
• Thiabendazole
• Viloxazine

This medication may also interact with the following:

• Acyclovir
• Alcohol
• Antihistamines for allergy, cough, and cold
• Baclofen
• Birth control pills
• Certain medications for anxiety or sleep
• Certain medications for blood pressure, heart disease, irregular heartbeat like amiodarone, mexiletine, propafenone, verapamil
• Certain medications for depression like amitriptyline, fluoxetine, sertraline
• Certain medications for seizures like phenobarbital, primidone
• Cimetidine
• Clonidine
• Famotidine
• General anesthetics like halothane, isoflurane, methoxyflurane, propofol
• Guanfacine
• Medications for sleep
• Medications that relax muscles for surgery
• Methyldopa
• Narcotic medications for pain
• Phenothiazines like chlorpromazine, prochlorperazine, thioridazine
• Ticlopidine
• Zileuton

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand up or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effects of this medication. Avoid alcoholic drinks.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy and drinking plenty of water may help. Contact your care team if the problem does not go away or is severe.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

• Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• CNS depression—slow or shallow breathing, shortness of breath, feeling faint, dizziness, confusion, trouble staying awake
• Hallucinations
• Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
• Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

• Constipation
• Dizziness
• Drowsiness
• Dry mouth
• Fatigue

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

• Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
• If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, take the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.