


pronounced as (dan' troe leen)


Dantrolene can cause severe liver damage. Do not use dantrolene for conditions other than those recommended by your doctor. Do not take more than the recommended amount prescribed by your doctor. Do not take dantrolene if you have liver disease. If you experience any of the following symptoms, call your doctor immediately: yellowing of the skin or eyes, dark urine, black tarry stools, nausea, vomiting, loss of appetite, pain in the upper right part of the stomach, or unusual bruising or bleeding.


Why is this medication prescribed?

Dantrolene is used to treat spasticity (muscle stiffness and tightness) or muscle spasms associated with spinal cord injuries, stroke, multiple sclerosis, or cerebral palsy. It is also used to prevent, treat, or reduce the risk of malignant hyperthermia (disorder that causes a fast rise in body temperature and muscle contractions), Dantrolene is in a class of medications called skeletal muscle relaxants. Dantrolene acts on the spinal cord nerves to treat spasticity and to prevent and treat malignant hyperthermia.

How should this medicine be used?

Dantrolene comes as a capsule to take by mouth. When used to treat spasticity, it is usually taken once a day for 7 days and then increased gradually every 7 days to three to four times a day. When used to prevent malignant hyperthermia, it is usually given three to four times a day, starting 1 or 2 days before surgery. When used after a malignant hyperthermia crisis, it is usually given in 4 divided doses for 1 to 3 days . Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dantrolene exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Your doctor will probably start you on a low dose of dantrolene for spasticity and gradually increase your dose, not more than once every 7 days. If your symptoms do not improve or get worse within 45 days of taking dantrolene, call your doctor.

Other uses for this medicine


What special precautions should I follow?

Before taking dantrolene,

  • tell your doctor and pharmacist if you are allergic to dantrolene, any other medications, or any of the ingredients in dantrolene capsules. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antidepressants; medications for anxiety; calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, Tiazac, others), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Procardia), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Verelan); estrogen-containing contraceptives (birth control pills, patches, rings, and injections); or estrogen replacement therapy; medications for mental illness; medications for seizures; sedatives; sleeping pills; or tranquilizers. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had muscle spasms from a rheumatic disorder, or heart or lung disease.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking dantrolene.
  • you should know that dantrolene 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 alcoholic beverages while you are taking dantrolene. Alcohol can make the side effects from dantrolene worse.

What should I do if I forget a dose?


What side effects can this medication cause?


  • muscle weakness
  • dizziness
  • diarrhea
  • fatigue

In addition to the symptoms mentioned in the IMPORTANT WARNING section, if you experience and of the following symptoms, call your doctor immediately:

  • seizures
  • difficulty breathing or slow, shallow breathing


What should I know about storage and disposal of this medication?




In case of emergency/overdose


Symptoms of overdose may include:

  • vomiting
  • diarrhea
  • muscle weakness
  • extreme tiredness
  • coma

What other information should I know?



Brand names

  • Dantrium®
Last Revised - 12/15/2019