Dantrolene Oral (patient information)

IMPORTANT WARNING

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 active 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, or severe nausea and vomiting.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to dantrolene.

Why this medication is prescribed

Dantrolene, a muscle relaxant, is used to treat spasticity or muscle spasms associated with spinal cord injuries, stroke, multiple sclerosis, cerebral palsy, or other conditions.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How this medication should be used

Dantrolene comes as a capsule to take by mouth. It usually is taken once a day at first and then increased gradually to two to four times a day. 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.

If you cannot swallow capsules, empty the contents into fruit juice and mix well just before taking the dose.

Special precautions

Before taking dantrolene:

• tell your doctor and pharmacist if you are allergic to dantrolene or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially diazepam (Valium); estrogen; medications for seizures, allergies, colds, or coughs; sedatives; sleeping pills; tranquilizers; and vitamins.
• tell your doctor if you have or have ever had liver, heart, rheumatic, or lung disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dantrolene, call your doctor immediately.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how dantrolene affects you.
• remember that alcohol can add to the drowsiness caused by this drug.
• you should plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Dantrolene may make your skin sensitive to sunlight.

What to do if you forget a dose

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for the missed one.

Side effects

Minor side effects

Dantrolene may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• muscle weakness
• drowsiness
• dizziness
• diarrhea
• fatigue
• difficulty swallowing

Severe side effects

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

• seizures

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

Storage conditions needed for this medication

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Other information

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Dantrium®