Tizanidine Side Effects

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Tizanidine is a popular muscle relaxant that has been helping people manage spasticity due to various medical issues. Although well-tolerated, the medication can cause certain side effects in people, especially when not taken as prescribed. Hence, starting this medication must understand the possible side effects and strictly adhere to the recommended dosage and prescription to minimize unwanted health risks.

A Quick Rundown of Tizanidine

Tizanidine belongs to a category of drugs known as central alpha-2 adrenergic receptor antagonists. Health professionals may prescribe a fast-acting muscle relaxant to keep muscle spasticity under control. Inside the body, Tizanidine increases the inhibitions of motor neurons in the brain. These neurons are responsible for sending messages to the muscles to contract, and their inhibition cause relaxation and relief from painful spasms.

In general, a doctor may prescribe Tizanidine to relieve muscle spasms secondary to the following conditions:

  • Stroke
  • Multiple sclerosis
  • Brain injury
  • Spinal cord injury
  • Musculoskeletal injury

Tizanidine comes in the form of 2 to 4 mg of oral tablets and up to 6 mg of capsules. According to the most recent information from the Food and Drug Administration (FDA), the medicine is ineffective below 8 mg, but a single adequate dosage of Tizanidine can relieve spasticity for many hours. Most experts initially start people on 2 to 4 mg and observe them for side effects. As the body gets used to the medication, a clinician may keep increasing the dose gradually until optimal symptomatic relief is achieved. Remember that the total daily dosage must never exceed a total of 36 mg per day in 24 hours.

Tizanidine Side Effects Profile

Using Tizanidine oral tablets can lead to multiple common and rare side effects. Let’s look at the side effects profile of this medication in detail below.

More Common Side Effects

People using Tizanidine may experience the following side effects quite commonly:

  • Dry mouth
  • Weakness
  • Tiredness
  • Vision problems
  • Dizziness
  • Constipation
  • Urinary tract infection
  • Vomiting
  • Runny nose
  • Trouble speaking
  • Sore throat

These side effects are likely to go away within a few days or weeks. However, contact a doctor if they become more severe or do not go away within weeks.

Serious Side Effects

Sometimes, using Tizanidine may cause serious side effects for which urgent medical attention may be needed. If you experience any of the side effects mentioned below, call the local emergency services at once:

  • Hallucinations: It includes seeing things that are not real.
  • Extremely Low Blood Pressure: The symptoms may include lightheadedness or dizziness when lying down or standing up.
  • Delusions: The symptoms may include believing things or having concepts that are not based on reality.
  • Sedation: The symptoms of extreme sedation may make weakness, dizziness, sleepiness, or fatigue.
  • Liver Damage: The common symptoms of liver damage may include yellowing of the skin and white parts of the eyes and frequent bruising or internal bleeding.

Tizanidine Drug Interactions to Keep in Mind

Tizanidine tablets can interact with many vitamins, herbs, or medications a person is already taking. These interactions may change how either of the drugs works, preventing them from working efficiently or cause side effects. To avoid these interactions, a doctor must carefully examine and manage all medications a person is currently taking before starting them on Tizanidine. Patients also carry the responsibility to make their clinicians aware of all medications and supplements they are currently taking. Following are some examples of drugs that can interact with Tizanidine.


Taking Tizanidine with this medication can increase the side effects of both. Some common side effects may include extreme drowsiness, decreased heart rate, and low blood pressure.

Fluoroquinolone Antibiotics

All antibiotics categorized as fluoroquinolones, such as moxifloxacin and levofloxacin, can interact with Tizanidine to cause decreased blood pressure and heart rate. Ciprofloxacin is the only medication from this antibiotic category safe enough to pair with Tizanidine.

Heart Rhythm Controlling Drugs

These medicines may include mexiletine, amiodarone, and verapamil. Together with Tizanidine, it can lead to dangerously low heart rate and blood pressure making a person feel dizzy and even collapse.


These medications include famotidine and cimetidine, and people commonly use it to manage acid burn in the stomach. However, these apparently safe medicines can react with Tizanidine to enhance the latter’s side effects.

Oral contraceptives

Women using oral contraceptives must be careful about combining them with Tizanidine as they may experience extreme sedation as a side effect that can prevent them from functioning safely in day-to-day life.


This medication is commonly used to manage viral infections and can react with Tizanidine to cause hypotension and bradycardia.


Increased side effects of combining ticlopidine with Tizanidine may include decreased blood pressure, heart rate, and extreme drowsiness.


In addition to the drugs mentioned above, using Tizanidine with benzodiazepines, like diazepam, lorazepam, and alprazolam, can cause severe sedation. The same effects can occur when combining Tizanidine with antidepressants like nortriptyline, protriptyline, and amitriptyline.

Tizanidine Warnings and Precautions

People taking Tizanidine oral tablets must keep the following warnings in mind while taking the medication:

Allergy Warning

People sensitive to Tizanidine may experience a severe allergic reaction, triggering symptoms such as itching, trouble breathing, and tongue and throat swelling. If you feel that the medication is bringing up an allergic reaction, call the local emergency services at once. If you previously experienced an allergic reaction to Tizanidine, do not ever take it again, as it may lead to potentially fatal consequences.

Alcohol Interactions Warning

Consuming alcoholic beverages and drinks with Tizanidine can increase the levels of the latter in the body, causing more serious side effects.

Warnings for People with Co-Existing Health Issues

People with the following co-existing issues may also need to be careful while using Tizanidine:

  • Decreased Liver Function: Talk to the doctor about Tizanidine’s safety. A doctor may prescribe a lower dose and monitor the liver functions frequently to ensure the medication is not worsening them.
  • Renal Impairment: People with ongoing kidney issues may not tolerate the usual dose of Tizanidine. Hence, a doctor may ask them to take it in reduced doses and keep an eye on their renal functions to ensure that everything is going smoothly.

Miscellaneous Findings

  • Tizanidine is a category C pregnancy medication which means that animal studies have confirmed its adverse effects on the developing baby in mothers taking this drug. However, human trials are currently insufficient to provide a conclusive result. Talk to a doctor about using Tizanidine if you are pregnant or planning to conceive soon to ensure that your baby remains risk-free.
  • The effects of Tizanidine have not been studied in children. Hence, those under the age of 18 years must not use it.
  • Seniors, especially those over 65 years, must consider talking to a doctor as their bodies may not be well-equipped to handle the usual dose of Tizanidine.
  • Experts are unsure if Tizanidine can pass into breastmilk and cause side effects in the breastfed child. Hence, all nursing mothers must talk to a doctor regarding the possible risks of taking the medication during breastfeeding.

Taking Tizanidine: Important Considerations to Remember

Keep the following considerations in mind if you have recently started taking Tizanidine:

General Considerations

Tizanidine can be taken with or without food. Whichever way you prefer, be consistent with it and take the tablet the same way every time.

Avoid crushing or cutting the tablet.


Store Tizanidine tablets at 77°F to prevent them from becoming restructured and ineffective.

Avoid storing the medication in damp or moist areas, including bathrooms.


A prescription for Tizanidine is refillable, meaning you may not need a new prescription every time it ends. A doctor can write down the number of pills you are authorized to take on your one-time prescription.


If you are on Tizanidine and traveling:

  • Always keep the medication with you. If taking a flight, keep it in your carry-on instead of putting it in a checked bag.
  • Always carry it in the original prescription-labeled container, as airport security may check it.
  • The X-ray machines at the airport cannot change or alter the medication or its composition.
  • Do not leave the medication in the car, especially when the temperature is very cold or hot.

Preventing Tizanidine Side Effects

To minimize the risk of experiencing Tizanidine long-term side effects, a doctor may offer regular monitoring. This monitoring is to ensure that everyone on these tablets remains safe without developing any complications. Following are some investigations that may possibly include in every follow-up:

Liver Function

A doctor may perform a blood test to check the liver function and determine how well the liver is functioning. If the results are deranged, they may consider reducing the dose of Tizanidine to avoid side effects.

Kidney Functions

These blood tests determine how well the kidneys are working. If they pick up any problem, a doctor may consider lowing the dose of Tizanidine as people with impaired kidney functions cannot excrete the medication easily from the body.

Blood Pressure

A doctor may check the blood pressure to ensure that the medication does not cause any drops.


What is the best way to take Tizanidine without any side effects?

Tizanidine comes in the form of oral tablets with variable strengths. The individual dosage, drug form, and frequency may vary depending on the following factors:

  • Age
  • The condition it is treating
  • The severity of the underlying condition it is treating
  • Other co-existing medical issues
  • How a person reacts to the first dose

In general, experts advise taking the medication with water as directed on the prescription label. People can take it with or without food as they like. Experts advise taking Tizanidine the same way and continuing the use until a doctor tells them to stop. Discontinuing it too soon may sometimes lead to serious side effects.

What if I miss a dose of Tizanidine?

If you miss a dose, the best thing to do is take it as soon as you remember. If it is almost time for the next dose, skip the one you missed and take the next scheduled one. Taking two doses close together can cause Tizanidine side effects.

Is the senior dosage for Tizanidine different from that for young adults?

Senior adults, usually over the age of 65 years, usually have deteriorating kidneys that do not function as efficiently as in young adults. This can cause their body to process Tizanidine and other drugs more slowly, causing it to stay in the body longer and increasing the risk of side effects. Hence, a doctor may start them on a lower dose or maintain a different dosing schedule altogether to keep the medicine from building up in the body.

Does Tizanidine make you sleepy?

Tizanidine can cause drowsiness, dizziness, unsteadiness, clumsiness, and lightheadedness in some people as a side effect. Hence, it is imperative to understand how this medication affects you before considering using machines, driving, or performing any other activity requiring coordination and high alertness.

Is Tizanidine a potent muscle relaxer?

Tizanidine is a fast-acting potent muscle relaxant that experts prescribe to control muscle spasticity. It increases the inhibition in motor neurons of the brain to stop them from contracting the muscles.

Is 4 mg of tizanidine strong?

Most people begin using 2 to 4 mg of Tizanidine as it is a low dose and causes minimal risk of side effects. Research conducted on this medication has shown that any dosage below 8 mg is ineffective for most people. Hence, healthcare experts increase it by 2 to 4 mg every week until patients start experiencing the best effects.

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