DrugindexOnline^{2nd edition}

Generic name: Tizanidine
Brand names: Zanaflex

Why is Zanaflex prescribed?

Zanaflex relaxes the tense, rigid muscles caused by spasticity. It is prescribed for people with multiple sclerosis, spinal cord injuries, and other disorders that produce protracted muscles spasms. The effect of the drug peaks 1 to 2 hours after each dose and is gone within 3 to 6 hours, so it's best to schedule doses for shortly before the daily activities when relief of spasticity is most important.

Most important fact about Zanaflex

Zanaflex causes drowsiness in almost half the people who use it. It also tends to reduce blood pressure in many people, frequently leading to dizziness and light-headedness. The likelihood of significant drowsiness increases when Zanaflex is combined with other spasticity drugs, such as Lioresal, Klonopin, and Valium. When taking Zanaflex, always be cautious about driving or operating dangerous machinery.

How should you take Zanaflex?

Take Zanaflex exactly as directed. The danger of side effects increases with the size of the dose.

--If you miss a dose...

Doses should be taken only as needed. Allow 6 to 8 hours between doses. Take no more than 3 a day. Never double the dose.

--Storage instructions...

Store at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe to continue using Zanaflex.

• More common side effects may include:
  Abnormal movements, blurred vision, constipation, dizziness, drowsiness, dry mouth, flu-like symptoms, frequent urination, low blood pressure, nervousness, runny nose, slow heartbeat, sore throat, speech disorders, urinary and other infections, vomiting, weakness or fatigue

Why should Zanaflex not be prescribed?

You'll need to avoid Zanaflex if it gives you an allergic reaction.

Special warnings about Zanaflex

Researchers have little information on the long-term consequences of using Zanaflex in single doses of more than 8 milligrams, or in total amounts of more than 24 milligrams a day. If you require a higher dosage, previously unrecognized side effects could possibly appear.

Remember that Zanaflex can cause low blood pressure and should be used with caution if you are taking blood pressure medication. Be cautious, too, when first standing up. Dizziness and light-headedness are especially likely at that time.

Zanaflex has been known to cause liver injury in a few patients. If you have a liver condition, make sure the doctor knows about it. Alert your doctor immediately if you develop warning signs of a liver problem such as loss of appetite, nausea, vomiting, or yellow skin or eyes.

You'll need a reduced dose of Zanaflex if you have a kidney problem. Be sure to inform the doctor about your condition, and be quick to report side effects such as dry mouth, drowsiness, dizziness, and weakness. They could be signs that your dose is too high.

Use Zanaflex with caution if spasticity helps you maintain your posture and balance while walking, or helps to increase other functions.

Although there are no reports of eye damage from Zanaflex, it has occurred in animal tests. Be sure to report any vision problems to your doctor.

Zanaflex has not been tested in children.

Possible food and drug interactions when taking Zanaflex

Oral contraceptives tend to boost the amount of Zanaflex in the system. If you are using an oral contraceptive, you'll probably need a smaller dose of Zanaflex.

Alcohol, or any drug that slows the nervous system (including other drugs taken for spasticity), increases the likelihood of drowsiness when taken with Zanaflex.

Special information if you are pregnant or breastfeeding

The effects of Zanaflex during pregnancy have not been adequately studied. It should be used during pregnancy only if clearly needed.

It's likely that Zanaflex makes its way into breast milk, although this has not been confirmed. Check with your doctor before using Zanaflex while nursing.

Recommended dosage

ADULTS

To minimize side effects, the doctor is likely to begin with a dosage of 4 milligrams, then increase the dose gradually. Doses of 8 milligrams provide relief for most people. No more than 3 doses should be taken each 24 hours. The maximum dose per day is 36 milligrams.

Overdosage

An overdose of Zanaflex can impair breathing and lead to coma. If you suspect an overdose, seek emergency treatment immediately.