What is Chlorzoxazone used for?
Chlorzoxazone is commonly used to treat muscle spasms/pain. It is usually used along with rest, physical therapy, and other treatment. It works by helping to relax the muscles.
How should I take Chlorzoxazone?
Take this medication by mouth with or without food as directed by your doctor, usually 3 or 4 times a day.
The dosage is based on your medical condition and response to treatment. Do not increase your dose or take it more often than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.
Tell your doctor if your condition does not improve or if it worsens.
How do I store Chlorzoxazone?
Chlorzoxazone is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Chlorzoxazone in the bathroom or the freezer. There may be different brands of Chlorzoxazone that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.
You should not flush Chlorzoxazone down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.
Precautions & warnings
What should I know before using Chlorzoxazone?
Before taking chlorzoxazone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease.
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially drowsiness, or confusion. These side effects can increase the risk of falling.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
Is it safe during pregnancy or breast-feeding?
There are no adequate studies in women for determining risk when using this Chlorzoxazone during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this Chlorzoxazone. This Chlorzoxazone is pregnancy risk category N according to the US Food and Drug Administration (FDA).
FDA pregnancy risk category reference below:
- A=No risk,
- B=No risk in some studies,
- C=There may be some risk,
- D=Positive evidence of risk,
What side effects can occur from Chlorzoxazone?
Drowsiness, dizziness, lightheadedness, tiredness, upset stomach, or headache may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
This medication may rarely cause your urine to turn orange or reddish-purple. This effect is harmless and will disappear when the medication is stopped.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: confusion, black/bloody stools, vomit that looks like coffee grounds, easy bruising/bleeding, signs of infection (such as fever, persistent sore throat).
This medication may rarely cause very serious (possibly fatal) liver disease. Stop taking this medication and get medical help right away if you develop symptoms of liver disease, including: persistent nausea/vomiting, stomach/abdominal pain, yellowing eyes/skin, dark urine.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.
What drugs may interact with Chlorzoxazone?
Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana, drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), other muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Chlorzoxazone may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.
Does food or alcohol interact with Chlorzoxazone?
Chlorzoxazone may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.
What health conditions may interact with Chlorzoxazone?
Chlorzoxazone may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.
The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Chlorzoxazone.
What is the dose of Chlorzoxazone for an adult?
Usual Adult Dose for Muscle Spasm
250 to 750 mg orally 3 to 4 times a day.
The dosage may be reduced as the condition of the patient improves.
Renal Dose Adjustments
No adjustments recommended
Liver Dose Adjustments
Chlorzoxazone is contraindicated in patients with liver dysfunction.
If any signs or symptoms suggestive of liver dysfunction are observed, the drug should be discontinued.
Serious (including fatal) hepatocellular toxicity has been reported rarely in patients receiving chlorzoxazone. Patients should be instructed to report early signs and/or symptoms of hepatotoxicity such as fever, rash, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, or jaundice.
What is the dose of Chlorzoxazone for a child?
Usual Pediatric Dose for Muscle Spasm
125 to 500 mg orally 3 to 4 times a day.
Alternative dosing: 20 mg/kg/day in divided doses 3 to 4 times a day.
How is Chlorzoxazone available?
Chlorzoxazone is available in the following dosage forms and strengths:
What should I do in case of an emergency or overdose?
In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.
What should I do if I miss a dose?
If you miss a dose of Chlorzoxazone, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: January 15, 2018 | Last Modified: November 29, 2019
Chlorzoxazone. https://www.webmd.com/drugs/2/drug-10950/chlorzoxazone-oral/details. Accessed January 15, 2018.
Chlorzoxazone Dosage. https://www.drugs.com/dosage/chlorzoxazone.html. Accessed January 15, 2018.