Tizanidine hydrochloride (
Zanaflex®) is a prescription medication used to treat spasticity, a condition involving muscle spasms, cramps, and tightness that is often caused by
multiple sclerosis (
MS) or spinal cord injuries or diseases. It is short-acting (each dose only lasts for a few hours) and should be reserved for daily activities when spasticity control is most important.
As with any medicine, side effects are possible with tizanidine.
However, not everyone who takes the drug will experience problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or can be treated easily by you or your healthcare provider. Serious reactions are less common.
Some of the most common side effects of tizanidine include but are not limited to:
- Weakness, fatigue, or tiredness
- Drowsiness
- Dry mouth.
(Click Tizanidine Side Effects to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
What Should I Tell My Healthcare Provider?
Prior to taking this product, talk to your healthcare provider if you have:
- Low blood pressure (hypotension)
- A slow heart rate (bradycardia)
- Liver disease, such as liver failure, hepatitis, or cirrhosis
- Kidney disease, such as kidney failure (renal failure)
- Any allergies, including to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about all of the medicines you take, including prescription and nonprescription drugs, vitamins, and herbal supplements.
How Does Tizanidine Work?
Tizanidine belongs to a group of medications known as alpha-2 adrenergic agonists. It binds to and stimulates alpha-2 receptors, an action that inhibits motor neurons. This medication works centrally (in the spinal cord or brain), not directly on the muscles.
Some general considerations to keep in mind when taking this medicine include the following:
- Tizanidine comes in tablet and capsule forms. It is usually taken as needed, up to three times daily.
- The effects of a dose of this medication peak about one to two hours after taking it, and it will usually stop working within three to six hours. Keep this in mind when timing your doses.
- Taking the capsules with food decreases the peak level of medication in the bloodstream, but the opposite is true with the tablets (food increases the peak level of medication). It is important to take tizanidine consistently in the same way -- either with or without food.
- For the medication to work properly, it must be taken as prescribed. Do not stop taking it suddenly, especially if you have been taking it for quite a while.
Tizanidine Dosing Information
The dose of tizanidine your healthcare provider recommends will vary, depending on a number of factors, including:
- How you respond to this medication
- The severity of your condition
- Other medications you take
- Any other medical conditions you may have.
As is always the case, do not adjust your dose unless your healthcare provider specifically tells you to do so.
What If I Take an Overdose?
An overdose with this medication may be dangerous, and some deaths have been reported. If you happen to take too much tizanidine, seek immediate medical attention.
What Should I Do If I Miss a Dose?
If you forget to take your tizanidine dose, you may want to take it as soon as possible or skip the dose, depending on when you need the medication to work the best. Keep in mind that the effects of a dose peak about one to two hours after taking it, and the medicine usually stops working within three to six hours. Do not take a double dose.
Can I Buy Generic Tizanidine?
This medication is available in generic form
(see Generic Zanaflex for more information).
Brand-name tizanidine is made by Acorda Therapeutics, Inc. Generic versions are made by various manufacturers.
This medication comes in the following strengths and forms:
Brand-name tizanidine 2 mg tablets were once available, but the manufacturer stopped making them. Generic versions of the 2-mg tablets are still available.
