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Dantrium

Generic name: dantrolene (oral) [ DAN-troe-leen ]
Drug class: Skeletal muscle relaxants

Medically reviewed by Drugs.com on Jun 30, 2025. Written by Cerner Multum.

What is Dantrium?

Dantrium is used to treat muscle stiffness or twitching caused by conditions such as a spinal cord injury, stroke, cerebral palsy, or multiple sclerosis.

Dantrium is also used to treat or prevent muscle stiffness or twitching caused by malignant hyperthermia (a rapid increase in body temperature and severe muscle contractions) that can occur during surgery with certain types of anesthesia.

Dantrium may also be used for purposes not listed in this medication guide.

Dantrium side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Dantrium may cause life-threatening liver damage, especially if you take high doses or take the medicine long-term. Call your doctor at once if you have signs of liver problems: loss of appetite, nausea, vomiting, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Also call your doctor at once if you have:

Common side effects of Dantrium may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Dantrium may cause life-threatening liver damage, especially if you take high doses. Do not take Dantrium in larger amounts, or for longer than prescribed.

Call your doctor right away if you have signs of liver problems such as loss of appetite, nausea, vomiting, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Before taking this medicine

You should not use Dantrium if you are allergic to it, or if you have hepatitis, cirrhosis, or other liver disease.

You should also not take Dantrium at a time when you need muscle tone for safe balance and movement during certain activities. In some situations, it may be dangerous for you to have reduced muscle tone.

Tell your doctor if you have or have ever had:

It is not known if Dantrium will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Do not use Dantrium if you are breastfeeding.

Dantrium should not be given to a child younger than 5 years old.

How should I take Dantrium?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

If you take Dantrium within 3 or 4 hours before surgery, use just enough water needed to swallow the capsule. Tell your doctor if you have trouble swallowing Dantrium.

You may need frequent blood tests to check your liver function.

Call your doctor if your symptoms do not improve after 45 days, or if they get worse.

If you need surgery, tell the surgeon ahead of time that you are using Dantrium.

Store tightly closed at room temperature, away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include severe tiredness, fainting, muscle weakness, vomiting, diarrhea, or problems with urination.

What should I avoid while taking Dantrium?

Avoid driving or hazardous activity until you know how Dantrium will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

This medication can cause muscle weakness (especially in your hands and legs) and trouble swallowing. Use caution with daily activities to avoid injury before your muscle strength has returned completely.

Dantrium could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What other drugs will affect Dantrium?

Using Dantrium with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may affect Dantrium, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Does Dantrium interact with my other drugs?

Enter medications to view a detailed interaction report using our Drug Interaction Checker.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.