Chlorzoxazone is used to relieve pain and stiffness caused by muscle strains and sprains. It is used in combination with physical therapy, analgesics (such as aspirin or acetaminophen), and rest.

Side Effects Of Chlorzoxazone

Chlorzoxazone may cause side effects. Your urine may turn purple or red; this effect is not harmful. Tell your doctor if any of these symptoms are severe or do not go away:

  • upset stomach
  • drowsiness
  • dizziness
  • lightheadedness
  • weakness

If you experience any of the following symptoms, call your doctor immediately:

  • skin rash or itching
  • yellowing of the skin or eyes
  • stomach pain

Warnings & Precautions

Before taking chlorzoxazone:

  • tell your doctor and pharmacist if you are allergic to chlorzoxazone or any other medications.
  • tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially sedatives, sleeping pills, tranquilizers, and vitamins.
  • tell your doctor if you have or have ever had liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking chlorzoxazone, call your doctor.
  • talk to your doctor about the risks and benefits of taking chlorzoxazone if you are 65 years of age or older. Older adults should not usually take chlorzoxazone because it is not as safe or effective as other medications) that can be used to treat the same condition.
  • you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
  • ask your doctor about the safe use of alcohol during your treatment with chlorzoxazone. Alcohol can make the side effects of this medication worse.

Chlorzoxazone Dosage

Chlorzoxazone comes as a tablet to take by mouth. It usually is taken three or four times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take chlorzoxazone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.


Keep all appointments with your doctor.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription of chlorzoxazone.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.