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Dantrolene sodium oral

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.




WARNING: Infrequently, dantrolene may cause serious (sometimes fatal) liver problems. The risk is greater when using larger amounts (over 800mg/day) of dantrolene. This risk also appears to be greater in women, in people over 35 years of age, and in those people using other medications at the same time. To minimize the possibility of getting liver problems from this medication, your doctor will monitor you and test for liver conditions. Promptly notify your doctor if you have signs of liver problems such as yellowing of the eyes or skin, dark urine, severe stomach or abdominal pain, or unusual fatigue. Do not take more dantrolene than prescribed. If there is no noticeable improvement in your condition after 45 days of use, your doctor must be notified and dantrolene should be stopped.


Dantrolene relaxes muscles and relieves pain and discomfort associated with muscle spasms due to certain nerve disorders such as multiple sclerosis or spinal cord injuries or may be given for special cases of high fever.



This medication may also be used for muscle pain due to exercise or for heat stroke due to medications which decrease sweating.

How To Use

Take this drug exactly as directed by your doctor. The dosage will be adjusted for maximum benefit and minimal side effects. Follow your doctor's directions carefully. Do not increase your dose or take it more often than prescribed. Do not suddenly stop taking this drug without your doctor's approval.

Side Effects

May cause drowsiness, dizziness, weakness, tiredness or diarrhea. If these effects persist or worsen, notify your doctor. Notify your doctor promptly if you develop any of the following signs: liver problems (e.g., yellowing of your eyes or skin). Unlikely to occur but report any of the following symptoms to your doctor: constipation, black or tarry stools, nausea, vomiting, abdominal pain, headache, seizure, heart palpitations, loss of appetite, confusion, depression, increase in urination, sensitivity to sunlight. In the unlikely event you have an allergic reaction to this drug, seek immediate medical attention. Symptoms of an allergic reaction include: rash, itching, swelling, dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.


Before using this drug, tell your doctor your medical history especially of: liver or heart disease, breathing problems, any drug allergies. Because this drug may cause dizziness and/or drowsiness, use caution when driving or performing tasks that require alertness. Avoid alcohol consumption as it may increase the drowsiness and/or dizziness effects of this drug. Because this drug may increase your sensitivity to sunlight, limit your exposure to the sun. You may need to use a sunscreen and wear protective clothing. This drug should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. The manufacturer of this drug states this drug should not be used by nursing women.

Drug Interactions

Tell your doctor of all over-the-counter or prescription medication you may use including: sedatives, tranquilizers, narcotic pain relievers, sleeping pills, seizure medication, muscle relaxants, medications for depression, drugs that may affect the liver (e.g., long-term acetaminophen use, certain anti-cancer drugs). Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately.


Do not allow anyone else to use this medication. This drug may affect certain blood tests. Make sure you inform all your healthcare providers you use this drug.

Missed Dose

If you miss a dose, take it as soon as remembered if it is within an hour or so. If you do not remember until later, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (between 15 and 30 degrees C) away from moisture and heat. Do not store in the bathroom.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).