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 is this medication 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 should this medicine 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.
What special precautions should I follow?
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 should I do if I 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.
What side effects can this medication cause?
Dantrolene may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- muscle weakness
- difficulty swallowing
In addition to the symptoms mentioned in the IMPORTANT WARNING section, if you experience the following symptom, call your doctor immediately:
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 (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about storage and disposal of 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).
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.
In case of emergency/overdose
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What other information should I know?
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.