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dantrolene

Pronunciation

Generic Name: dantrolene (oral) (DAN troe leen)
Brand Name: Dantrium, Dantrium Intravenous, Revonto

What is dantrolene?

Dantrolene is a muscle relaxant.

Dantrolene is used to treat muscle spasticity (stiffness and spasms) caused by conditions such as a spinal cord injury, stroke, cerebral palsy, or multiple sclerosis.

Dantrolene is also used to prevent muscle stiffness and spasms caused by malignant hyperthermia (a rapid rise in body temperature) that can occur during surgery with certain types of anesthesia.

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

What is the most important information I should know about dantrolene?

You should not use dantrolene if you have liver disease such as hepatitis or cirrhosis. Do not use dantrolene at a time when muscle tone is needed to assure safe balance and movement for certain activities.

Dantrolene can cause life-threatening liver damage, especially if you take high doses or take the medicine long-term. You may be more likely to develop liver problems while taking dantrolene if you are a woman, if you are older than 35, or if you also take other medications. Ask your doctor about your individual risk.

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Call your doctor at once if you have signs of liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). These side effects may be most likely to occur between 3 and 12 months of your treatment with dantrolene.

While using dantrolene, you may need frequent blood tests to check your liver function.

What should I discuss with my healthcare provider before taking dantrolene?

You should not take this medicine if you are allergic to dantrolene, or if you have liver disease such as hepatitis or cirrhosis. Do not use dantrolene at a time when muscle tone is needed to assure safe balance and movement for certain activities. In some situations, it may endanger your physical safety to be in a state of reduced muscle tone.

Dantrolene can cause life-threatening liver damage, especially if you take high doses or take the medicine long-term. You may be more likely to develop liver problems while taking dantrolene if you are a woman, if you are older than 35, or if you also take other medications. Ask your doctor about your individual risk.

To make sure dantrolene is safe for you, tell your doctor if you have:

  • a history of liver disease;

  • a breathing disorder such as COPD (chronic obstructive pulmonary disease); or

  • heart disease, or a history of heart attack.

FDA pregnancy category C. It is not known whether dantrolene will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Dantrolene can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

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

How should I take dantrolene?

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using dantrolene.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take this medicine with a full glass of water. If you take dantrolene within 3 or 4 hours before surgery, use only enough water needed to swallow the pill.

While using dantrolene, you may need frequent blood tests to check your liver function.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

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

What should I avoid while taking dantrolene?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Drinking alcohol can increase certain side effects of dantrolene.

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

Dantrolene side effects

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

Call your doctor at once if you have signs of liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). These side effects may be most likely to occur between 3 and 12 months of your treatment with dantrolene.

Dantrolene can cause muscle weakness, which can affect your ability to swallow. Use caution to prevent choking while you are eating meals. Talk with your doctor if you are unable to eat because of this side effect.

Also call your doctor right away if you have:

  • muscle weakness;

  • severe drowsiness; or

  • vomiting, severe diarrhea.

Common side effects may include:

  • mild diarrhea;

  • weakness, drowsiness;

  • dizziness; or

  • tired feeling.

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.

See also: Side effects (in more detail)

Dantrolene dosing information

Usual Adult Dose for Malignant Hyperthermia:

For preoperative to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be susceptible:

IV: 2.5 mg/kg IV, starting approximately 75 minutes before anticipated anesthesia and infused over approximately 1 hour. This dose should be effective provided that the usual precautions, such as avoidance of established malignant hyperthermia triggering agents, are followed. Additional IV dantrolene may be indicated during anesthesia and surgery because of the appearance of early clinical and/or blood gas signs of malignant hyperthermia or because of prolonged surgery. Additional doses must be individualized.

Oral: 4 to 8 mg/kg/day orally in three or four divided doses for 1 or 2 days prior to surgery, with the last dose being given with a minimum of water approximately 3 to 4 hours before scheduled surgery. Adjustment can usually be made within the recommended dosage range to avoid incapacitation (weakness, drowsiness, etc.) or excessive gastrointestinal irritation (nausea and/or vomiting).

For postoperative use to prevent or attenuate the recurrence of signs of malignant hyperthermia when oral administration is not practical:

IV: dose must be individualized, starting with 1 mg/kg or more as the clinical situation dictates.

For use in the management of fulminant hypermetabolism of skeletal muscle characteristic of malignant hyperthermia crisis:

IV: (Starting dose = Minimum Dose) 1 mg/kg administered by continuous rapid intravenous push and continued until symptoms subside or the maximum cumulative dose of 10 mg/kg has been reached.

As soon as the malignant hyperthermia reaction is recognized, all anesthetic agents should be discontinued. The administration of 100% oxygen is also recommended.

If the physiologic and metabolic abnormalities reappear, the regimen may be repeated. It is important to emphasize that administration of dantrolene intravenous should be continuous until symptoms subside. The effective dose to reverse the crisis is directly dependent upon the individual's degree of susceptibility to malignant hyperthermia, the amount and time of exposure to the triggering agent, and the time elapsed between onset of the crisis and initiation of treatment.

Oral: 4 to 8 mg/kg/day orally in four divided doses administered for 1 to 3 days following a malignant hyperthermia crisis to prevent recurrence of the manifestations of malignant hyperthermia.

Usual Adult Dose for Chronic Spasticity:

For use in controlling the manifestations of clinical spasticity resulting from upper motor neuron disorders:

25 mg orally once daily for 7 days, then
25 mg three times a day for 7 days, then
50 mg three times a day for 7 days, then
100 mg three times a day.

Prior to administration, consideration should be given to the potential response to treatment. A decrease in spasticity sufficient to allow a daily function not otherwise attainable should be the therapeutic goal of treatment with dantrolene.

It is important to establish a therapeutic goal (regain and maintain a specific function such as therapeutic exercise program, utilization of braces, transfer maneuvers, etc.) before beginning dantrolene therapy.

Dosage should be titrated and individualized for maximum effect. The lowest dose compatible with optimal response is recommended.

Some patients will not respond until higher daily dosage is achieved. Each dosage level should be maintained for seven days to determine the patient's response. If no further benefit is observed at the next higher dose, dosage should be decreased to the previous lower dose.

Therapy with a dose four times daily may be necessary for some individuals. Doses higher than 100 mg four times daily should not be used.

In view of the potential for liver damage in long-term dantrolene use, therapy should be stopped if benefits are not evident within 45 days.

Usual Pediatric Dose for Malignant Hyperthermia:

For preoperative to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be susceptible:

IV: 2.5 mg/kg IV, starting approximately 75 minutes before anticipated anesthesia and infused over approximately 1 hour. This dose should be effective provided that the usual precautions, such as avoidance of established malignant hyperthermia triggering agents, are followed. Additional IV dantrolene may be indicated during anesthesia and surgery because of the appearance of early clinical and/or blood gas signs of malignant hyperthermia or because of prolonged surgery. Additional doses must be individualized.

Oral: 4 to 8 mg/kg/day orally in three or four divided doses for 1 or 2 days prior to surgery, with the last dose being given with a minimum of water approximately 3 to 4 hours before scheduled surgery. Adjustment can usually be made within the recommended dosage range to avoid incapacitation (weakness, drowsiness, etc.) or excessive gastrointestinal irritation (nausea and/or vomiting).

For postoperative use to prevent or attenuate the recurrence of signs of malignant hyperthermia when oral administration is not practical:

IV: dose must be individualized, starting with 1 mg/kg or more as the clinical situation dictates.

For use in the management of fulminant hypermetabolism of skeletal muscle characteristic of malignant hyperthermia crisis:

IV: (Starting dose = Minimum Dose) 1 mg/kg administered by continuous rapid intravenous push and continued until symptoms subside or the maximum cumulative dose of 10 mg/kg has been reached.

As soon as the malignant hyperthermia reaction is recognized, all anesthetic agents should be discontinued. The administration of 100% oxygen is also recommended.

If the physiologic and metabolic abnormalities reappear, the regimen may be repeated. It is important to emphasize that administration of dantrolene intravenous should be continuous until symptoms subside. The effective dose to reverse the crisis is directly dependent upon the individual's degree of susceptibility to malignant hyperthermia, the amount and time of exposure to the triggering agent, and the time elapsed between onset of the crisis and initiation of treatment.

Oral: 4 to 8 mg/kg/day orally in four divided doses administered for 1 to 3 days following a malignant hyperthermia crisis to prevent recurrence of the manifestations of malignant hyperthermia.

Usual Pediatric Dose for Chronic Spasticity:

For use in controlling the manifestations of clinical spasticity resulting from upper motor neuron disorders: 0.5 mg/kg orally once daily for 7 days, then
0.5 mg/kg three times a day for 7 days, then
1 mg/kg three times a day for 7 days, then
2 mg/kg three times a day.

Dosage should be titrated and individualized for maximum effect. The lowest dose compatible with optimal response is recommended.

Some patients will not respond until higher daily dosage is achieved. Each dosage level should be maintained for seven days to determine the patient's response. If no further benefit is observed at the next higher dose, dosage should be decreased to the previous lower dose.

Therapy with a dose four times daily may be necessary for some individuals. Doses higher than 100 mg four times daily should not be used.

In view of the potential for liver damage in long-term dantrolene use, therapy should be stopped if benefits are not evident within 45 days.

What other drugs will affect dantrolene?

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking dantrolene with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with dantrolene, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about dantrolene.
  • 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.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 5.01. Revision Date: 2013-12-05, 2:22:40 PM.

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