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What Is Tizanidine HCl?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

Tizanidine HCL (hydrochloride) is a prescription medication that treats painful muscle spasms, as might be caused by paralysis, multiple sclerosis, or injury. This drug comes in different forms, like capsules and tablets, and its exact dosage is often variable. Many medical contraindications are associated with tizanidine, and it also has over 200 major drug interactions. Additionally, the medicine may cause both benign and severe side effects.

Skeletal muscle relaxants like tizanidine HCL signal the brain by agonizing adrenergic receptors. Essentially, they bind to certain cells, acting very much as norepinephrine would, and this produces a reduction in muscle tone. The overall effect is that muscle spasms lessen or occur less often when the drug is used.

Tizanidine HCI is often prescribed to treat painful muscle spasms caused by paralysis or multiple sclerosis.
Tizanidine HCI is often prescribed to treat painful muscle spasms caused by paralysis or multiple sclerosis.

Getting the most satisfactory results from tizanidine HCL can be dependent on a number of factors. While the chemical strengths of the drug in different formulations are theoretically the same, patients may notice variations. The medication has been noted to act unpredictably, depending on the time of day it is used. A switch between formulations may be appreciable, too. Furthermore, taking the drug with or without food might alter drug metabolism and effects.

Additionally, tizanidine HCL is not appropriate for all individuals. Those who have a prolonged QT interval, which is a slight delay in the electrical system of the heart, should never use this medication because it creates a similar effect. Patients with kidney or liver disease or those who are pregnant may be offered another drug or a different dosing strategy.

There is also a very extensive list of drug interactions with tizanidine HCL. Hormonal birth control increases the strength of the drug, central nervous system depressants may intensify its effects, and other medications that elongate the QT interval are considered very dangerous. Patients should give doctors a complete list of drugs used, including any over-the-counter medicines and herbal or nutritional supplements. Moreover, they should always inform doctors they are taking tizanidine to avoid negative interactions with newly prescribed medications.

Patients who use this drug may have side effects that are benign or serious. Some fairly common adverse reactions include stomach pain and upset, dry mouth, and sensations of sedation or dizziness. Tizanidine HCL users could also experience weakness in the muscles, excess perspiration, reduced sensitivity or numbness, and anxious feelings. A few individuals develop a fever when they take this medication or may have a paradoxical reaction and experience rigidity in the muscles. These symptoms can be reported to doctors if they are bothersome, but they aren’t considered medically urgent.

In contrast, patients should seek emergency medical attention for negative adverse reactions like jaundice, allergy, and burning feelings during urination. Any confusion or hallucinations should be reported. Cardiac problems like pain or slow or fast heart rates are also medically urgent. Side effects may present a much more complex profile if tizanidine HCL is combined with other drugs.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...
Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...

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    • Tizanidine HCI is often prescribed to treat painful muscle spasms caused by paralysis or multiple sclerosis.
      By: Simone van den Berg
      Tizanidine HCI is often prescribed to treat painful muscle spasms caused by paralysis or multiple sclerosis.