Tizanidine HCL – Uses, Side Effects, and More
8.3 Nursing Mothers
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when tizanidine hydrochloride is administered to a nursing woman.
Tizanidine, Oral Tablet
Tizanidine is a prescription drug that comes as an oral tablet and an oral capsule.
Tizanidine oral tablet is available as a brand-name drug Zanaflex. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in all strengths or forms as the brand-name drug.
Why it’s used
Tizanidine oral tablet is used to manage muscle spasms. Symptoms can include muscle tightness, pain, or stiffness. This drug is often used for people with multiple sclerosis, spinal cord injury, or muscle spasticity.
How it works
Tizanidine belongs to a class of drugs called alpha-2-adrenergic agonists. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.
Tizanidine reduces the activity of nerves in the spinal cord that control muscles. This helps to reduce muscle spasms.
Just under half – 49% – of Americans get their health insurance through their employer, according to the Henry J. Kaiser Family Foundation. Another 19% of Americans are insured under Medicaid, 14% under Medicare, seven% under non-group plans and two% under other public insurers, while nine% of U.S. citizens remain uninsured.
Tizanidine oral tablet may cause drowsiness. It may also cause other side effects.
More common side effects
The more common side effects of tizanidine can include:
- dry mouth
- tiredness
- weakness
- dizziness
- urinary tract infection
- constipation
- vomiting
- trouble speaking
- runny nose
- sore throat
- vision problems
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk with your doctor or pharmacist.
Serious side effects
Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
- Hallucinations. Symptoms can include:
- seeing things that aren’t real
- believing things that aren’t real
- dizziness or lightheadedness, especially when standing after sitting or lying down
- increased bleeding or bruising
- yellowing of your skin or the whites of your eyes
- dizziness
- weakness
- fatigue and sleepiness
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare professional who knows your medical history.
Tizanidine oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.
To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk with your doctor or pharmacist.
Examples of drugs that can cause interactions with tizanidine are listed below.
Drugs that should not be used with tizanidine
Do not take these drugs with tizanidine. When used with tizanidine, these drugs can cause dangerous effects in the body. Examples of these drugs include:
- Fluvoxamine and ciprofloxacin (Cipro). Using these drugs with tizanidine may cause very low blood pressure. It may also cause increased drowsiness or decreased muscle control.
- Other alpha-2 agonist medications such as clonidine, methyldopa, or guanfacine. Using these drugs with tizanidine can cause very low blood pressure.
Drugs that increase the risk of side effects from tizanidine
Taking tizanidine with certain medications raises your risk for side effects from tizanidine. This is because the amount of tizanidine in your body is increased. Avoid using these drugs with tizanidine if possible. Examples of these drugs include:
- Zileuton. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Certain antibiotics called fluoroquinolones (other than ciprofloxacin), such as levofloxacin, moxifloxacin, or gemifloxacin. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Certain heart rhythm drugs such as amiodarone, mexiletine, propafenone, or verapamil. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Antacids such as cimetidine or famotidine. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Oral contraceptives. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Acyclovir. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
- Ticlopidine. Increased side effects can include decreased blood pressure, decreased heart rate, or extreme drowsiness.
Using tizanidine with the following drugs can cause excessive sedation (drowsiness):
- benzodiazepines such as alprazolam, lorazepam, or diazepam.
- opioids such as morphine, methadone, or oxycodone.
- certain antidepressants such as amitriptyline, nortriptyline, or protriptyline.
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare professional about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Tizanidine oral tablet comes with several warnings.
Allergy warning
Tizanidine can cause a severe allergic reaction. Symptoms can include:
- trouble breathing
- itching
- swelling of your throat or tongue
If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 911 or go to the nearest emergency room.
Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).
Alcohol interaction warning
The use of drinks that contain alcohol increases the amount of tizanidine in your body. This can cause increased side effects from tizanidine.
Warnings for people with certain health conditions
For people with decreased liver function. Talk with your doctor about whether tizanidine is safe for you. If you take this drug, your doctor may give you a lower dose. Also, your doctor should check your liver function at the start of treatment. They may check it again 1 month after your maximum dose has been prescribed.
For people with decreased kidney function. Talk with your doctor about whether tizanidine is safe for you. If you take this drug, your doctor may give you a lower dose. Also, your doctor will watch for buildup of too much tizanidine in your body. Symptoms can include dry mouth, dizziness, or drowsiness.
Warnings for other groups
For pregnant women. Tizanidine is a category C pregnancy drug. That means two things:
- Research in animals has shown adverse effects to the fetus when the mother takes the drug.
- There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.
Talk with your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the fetus. Call your doctor if you become pregnant while taking this drug.
For women who are breastfeeding. It’s not known if tizanidine passes into breast milk and causes side effects in a child who is breastfed. Talk with your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.
For seniors. The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk for side effects.
For children. This medication has not been studied in children. It should not be used in people younger than 18 years.
This dosage information is for tizanidine oral tablet. All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:
- your age
- the condition being treated
- how severe your condition is
- other medical conditions you have
- how you react to the first dose
Forms and strengths
Generic: Tizanidine
Brand: Zanaflex
Dosage for muscle spasms
Adult dosage (ages 18 years and older)
- Typical starting dosage: 2 mg every 6–8 hours as needed.
- Dosage increases: Your doctor may increase your dosage by 2–4 mg until your symptoms are controlled. They will wait 1–4 days between any increases.
- Maximum dosage: 3 doses in 24 hours.
Child dosage (ages 0–17 years)
This medication has not been studied in children. It should not be used in people younger than 18 years.
Senior dosage (ages 65 years and older)
The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk for side effects. Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.
Tizanidine oral tablet is used for long-term or short-term treatment. It comes with serious risks if you don’t take it as prescribed.
If you stop taking the drug suddenly or don’t take it at all: If you stop taking tizanidine suddenly, you are at risk for withdrawal symptoms. This risk is higher if you’ve been taking high doses of the drug or taking it for a long period of time.
Withdrawal symptoms can include high blood pressure, a fast heart rate, or worsened muscle spasms. If you decide to stop this drug, your doctor should slowly decrease your dosage by 2–4 mg per day.
If you don’t take this drug at all, your muscle spasms may not improve.
If you miss doses or don’t take the drug on schedule: Your medication may not work as well or may stop working completely. If you miss too many doses, you may have withdrawal symptoms.
If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:
- extreme tiredness
- confusion
- coma
- decreased heart rate
- severe decrease in blood pressure
- slowed breathing
If you think you’ve taken too much of this drug, call your doctor or seek guidance from the American Association of Poison Control Centers at 800-222-1222 or through their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.
What to do if you miss a dose: Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.
How to tell if the drug is working: You should have fewer symptoms of muscle spasms. These symptoms can include muscle tightness, pain, or stiffness.
Keep these considerations in mind if your doctor prescribes tizanidine oral tablet for you.
General
- You can take tizanidine with or without food. But you should be consistent. Take it the same way each time.
- You can cut or crush the tablet.
Storage
- Store tizanidine tablets at 77°F (25°C). You can store them for a short time at temperatures between 59°F and 86°F (15°C and 30°C).
- Don’t store this medication in moist or damp areas, such as bathrooms.
Refills
A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.
Travel
When traveling with your medication:
- Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
- Don’t worry about airport X-ray machines. They can’t hurt your medication.
- You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
- Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.
Clinical monitoring
You and your doctor should monitor certain health issues. This can help make sure you stay safe while you take tizanidine. These issues include:
- Kidney function. Blood tests can check how well your kidneys are working. If your kidneys aren’t working well, your doctor may lower your dosage of this drug.
- Liver function. Blood tests can check how well your liver is working. If your liver isn’t working well, your doctor may lower your dosage of this drug.
- Blood pressure. Your doctor may check your blood pressure to make sure that it does not get too low while you’re taking this drug.
Availability
Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead to make sure your pharmacy carries it.
Insurance
Many insurance companies require a prior authorization for this drug. This means your doctor may need to get approval from your insurance company before your insurance company will pay for the prescription.
There are other drugs available to treat your condition. Some may be better suited for you than others. Talk with your doctor about other drug options that may work for you.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
Last medically reviewed on July 22, 2021
Tizanidine HCL – Uses, Side Effects, and More
This medication is used to treat muscle spasms caused by certain conditions (such as multiple sclerosis, spinal cord injury). It works by helping to relax the muscles.
How to use Tizanidine HCL
Take this medication by mouth as directed by your doctor, usually every 6 to 8 hours.
The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor’s instructions carefully. Do not take more than 36 milligrams a day or more than 3 doses in a 24-hour period.
Your body will absorb this medication differently depending on whether you take it as a tablet or capsule, whether you take it with food or on an empty stomach, or if you sprinkle the contents of the capsule on food. Be sure to discuss with your doctor how to take this medication to determine the best way to take your dose, especially when changes to your dose are being considered or if your doctor prescribes a different form of tizanidine (such as tablet or capsule).
If you suddenly stop using this medication, you may have withdrawal symptoms (such as anxiety, tremor, increased blood pressure/heart rate/muscle tenseness). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used tizanidine for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal.
Tell your doctor if your condition does not improve or if it worsens.
Side Effects
Dry mouth, drowsiness, dizziness, lightheadedness, constipation, weakness, and tiredness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: fainting, mental/mood changes (such as hallucinations), slow/irregular heartbeat, vision changes (such as blurred vision).
Tizanidine has rarely caused very serious (rarely fatal) liver disease. Tell your doctor right away if you develop symptoms of liver disease, including: persistent nausea/vomiting, severe stomach/abdominal pain, dark urine, yellowing eyes/skin.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Precautions
Before taking tizanidine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: low blood pressure, kidney disease, liver disease.
This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially dizziness and drowsiness. These effects can increase the risk of falling.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
Interactions
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.
Some products that may interact with this drug include: certain drugs to treat high blood pressure (alpha agonists such as clonidine, methyldopa).
Other medications can affect the removal of tizanidine from your body, which may affect how tizanidine works. Examples include birth control pills, ciprofloxacin, fluvoxamine, viloxazine, among others.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), other muscle relaxants, and opioid pain relievers (such as codeine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
