Tizanidine is a prescription drug that can cause addiction to develop. Learn about the signs of tizanidine use and the dangerous effects of abusing the drug.

Tizanidine, also known by its trade name Zanaflex, is a muscle relaxant medication used for treating muscle spasticity. Tizanidine is legally available with a prescription in the United States, but drug dealers sell the drug for illicit use.

Tizanidine is an especially toxic medication with many serious side effects and dangerous interactions with other medications, such as birth control pills. Tizanidine’s toxicities and side effects are worsened by other drugs such as opioidscannabisstimulants, and benzodiazepines.

Symptoms of Tizanidine Abuse

People who use tizanidine that was not prescribed to them, or who are taking more than the prescribed dose, are considered to be abusing the drug. Tizanidine is a controlled substance and should only be used under the direction and care of a licensed prescriber. Using someone else’s prescription, or letting someone else use your prescription, is illegal and punishable by fines and jail time.

Physical Symptoms of Tizanidine

Drugs affect people differently, so not everyone will experience the same symptoms from taking the same type of drug. However, some common symptoms are usually observed in individuals taking specific types of drugs. Tizanidine has a large number of common and prevalent side effects including:

  • Low blood pressure, especially with dose increases
  • Rebound high blood pressure when decreasing the dose
  • Slow heart rate
  • Sedation severe enough to interfere with daily activities and make driving unsafe. This effect can be worsened by the use of other sedative drugs, such as opioids, cannabis or benzodiazepines.
  • Allergic reactions, including anaphylactic shock
  • Body temperature instability
  • Dry mouth
  • Dizziness
  • Withdrawal from tizanidine, especially after prolonged use, high doses or use with narcotics, can cause dangerous effects, such as high blood pressure, rapid heart rate, tremors, and muscle stiffness
  • An overdose

Psychological Symptoms of Tizanidine

Much like the physical symptoms of tizanidine, psychological symptoms may occur in some individuals taking the drug. Tizanidine is psychoactive, meaning that it crosses the blood-brain barrier and changes the brain’s chemistry. As such, the drug has a few serious, psychological side effects:

The psychological side effects of tizanidine are worsened by the concurrent use of other psychoactive medications, especially alcohol, opioids, and sedatives.

Other Tizanidine Side Effects

Tizanidine can have serious side effects in people whose kidneys are not functioning properly, as the body’s ability to clear the drug becomes greatly impaired and toxicity can develop quickly. Likewise, in people with liver problems, serious toxicity from tizanidine can develop rapidly. This danger is a particular concern for people who may have factors that affect their liver health, such as:

A particularly concerning aspect of tizanidine use is that it has dangerous drug-to-drug interactions with some common medications. People who take tizanidine without a prescription are often unaware of these interactions. Prescription medications that interact adversely with tizanidine include:

  • Certain birth control pills
  • Certain antibiotics
  • Certain antidepressant and anti-anxiety medications

Effects of Long-Term Tizanidine Abuse

Long-term use of tizanidine forces the body to adjust to the negative effects of the drug. For example, the body purposely increases blood pressure to compensate for the blood pressure-lowering effects of the drug, increases the heart rate to compensate from the heart rate-lowering effects, and suffers disruption of its normal muscle control function.

Signs of Tizanidine Addiction

Signs of addiction to tizanidine may go unnoticed by the individual living with the addiction or their loved ones, as the individual may be in denial and trying to hide the drug use. Signs of addiction include:

  • Using the drug when it’s not prescribed or in doses above the prescribed amount
  • Continuing to take the drug after it’s no longer required for a medical purpose
  • The inability to control the use of the drug
  • Obsessive or persistent thoughts about the drug
  • Drug use interfering with normal functions
  • Obtaining the drug illegally
  • Tolerance developing requiring escalating doses
  • Withdrawal symptoms occurring when trying to stop drug use
  • Using the drug other than for its legitimate purpose
  • Secretive drug use, including lying about its use
  • The use of other drugs, including alcohol, at the same time
  • Willingness to spend large amounts of time and money to obtain the drug

Tizanidine Addiction Intervention

Tizanidine is a dangerous medication with many toxicities. People abusing the drug require specialized care to safely taper off and withdraw from the drug and to assess for any physical effects that they may be suffering from the drug use, especially to the internal organs. Medically supervised detoxification is advised.

If you or a loved one struggle with drug addictioncontact The Recovery Village to speak with a representative about how personalized treatment programs can help. By addressing any co-occurring mental health disorders along with the addiction, The Recovery Village helps patients receive the support they need to live a healthy, sober life.

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Editor – Thomas Christiansen
With over a decade of content experience, Tom produces and edits research articles, news and blog posts produced for Advanced Recovery Systems. Read more
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Medically Reviewed By – Dr. Andrew Proulx, MD
Andrew Proulx holds a Bachelor of Science in Chemistry, an MD from Queen's University, and has completed post-graduate studies in medicine. He practiced as a primary care physician from 2001 to 2016 in general practice and in the ER. Read more

Drug Enforcement Administration. “Controlled substance schedules.” February 28, 2019. Accessed May 23, 2019.

Food and Drug Administration. “Tizanidine: highlights of prescribing information.” October 4, 2013. Accessed May 23, 2019.

Jones S., Sandhu H., Preston C.. “Tizanidine interactions.” The Pharmaceutical Journal, February 10, 2015. Accessed May 23, 2019.

Suárez-Lledó A., Padullés A., Lozano T., Cobo-Sacristán S., Colls M., Jódar R. “Management of Tizanidine Withdrawal Syndrome: A case report.” Clinical Medicine Insights: Case Reports, February 13, 2018. Accessed May 23, 2019.

Witenko C., Moorman-Li R., Motycka C., Duane K., Hincapie-Castillo J., Leonard P., et al. “Considerations for the appropriate use o[…]acute low back pain.” Pharmacy and Therapeutics, June, 2014. Accessed May 23, 2019.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.