Back Pain Home > Zanaflex Side Effects

Common side effects of Zanaflex include dry mouth, low blood pressure, and drowsiness. While most reactions to this drug are mild, more serious problems may occur; however, these are generally rare. Tell your healthcare provider immediately if you develop serious side effects, such as hallucinations, yellow skin, wheezing, or difficulty breathing.

An Introduction to Zanaflex Side Effects

As with any medicine, side effects are possible with Zanaflex® (tizanidine hydrochloride). However, not everyone who takes the medication will have 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 are treated easily by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with this medication. Your healthcare provider can discuss a more complete list of Zanaflex side effects with you.)

Common Side Effects of Zanaflex

Zanaflex has been studied extensively in clinical trials. In these studies, side effects occurring in the group of people taking Zanaflex were documented and compared to those that occurred in a similar group of people taking a placebo (a "sugar pill" with no active ingredients).
Based on these studies, the most common side effects of Zanaflex tablets included:
  • Drowsiness -- in up to 92 percent of people
  • Dry mouth -- up to 88 percent of people (see Zanaflex and Dry Mouth)
  • Weakness, fatigue, or tiredness -- up to 78 percent
  • Dizziness -- up to 45 percent
  • Low blood pressure (hypotension) -- up to 33 percent
  • A slow heart rate (bradycardia) -- up to 10 percent
  • Urinary tract infection (UTI), such as a bladder infection -- up to 10 percent.
Other common reactions (occurring in 3 to 6 percent of people) included:
  • Infection
  • Constipation
  • Increased liver enzymes (found using a blood test)
  • Vomiting
  • Speech problems
  • Blurred vision
  • Frequent urination
  • Flu symptoms (such as a fever and chills)
  • Nervousness
  • Sore throat
  • Runny or stuffy nose
  • Abnormal, involuntary muscle movements.
Written by/reviewed by:
Last reviewed by: Kristi Monson, PharmD;
Last updated/reviewed:
List of references (click here):
Other Articles in This eMedTV Presentation




Related Channels

eMedTV Links
Copyright © 2006-2020 Clinaero, Inc.

eMedTV serves only as an informational resource. This site does not dispense medical advice or advice of any kind. Site users seeking medical advice about their specific situation should consult with their own physician. Click Terms of Use for more information.

This site complies with the HONcode standard for trustworthy health information:
verify here.