Dantrolene relieves spasms and increases muscle tone caused by multiple sclerosis, stroke, or brain or spinal injury. May cause drowsiness. Do not drive until you know how it affects you.
Dantrolene is a prescription medication used to relieve spasms and increased muscle tone caused by multiple sclerosis, stroke, or brain or spinal injury. Dantrolene belongs to a group of drugs called muscle relaxants. Dantrolene causes muscle relaxation by interfering with calcium release within the muscle.
This medication comes in the form of a capsule and a liquid for injection. The capsule is usually taken by mouth 3 or 4 times daily. The injection is given directly into a vein (IV) by a healthcare provider.
Common side effects include diarrhea, drowsiness, and dizziness. Do not drive or operate machinery until you know how it affects you. It is best to avoid alcohol while taking dantrolene.
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Uses of Dantrolene
Dantrolene is a prescription medication, which in capsule form, is used to relieve spasms and increased muscle tone caused by multiple sclerosis, stroke, or brain or spinal injury.
Dantrolene capsules and injection are both approved to treat or prevent malignant hyperthermia, an inherited, potentially fatal condition in which body temperature quickly rises and severe muscle contraction occurs when the affected person receives anesthesia during surgery.
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.
Dantrolene Brand Names
Dantrolene Drug Class
Dantrolene is part of the drug class:
Side Effects of Dantrolene
Common side effects include:
- feeling of discomfort (malaise)
- loss of grip strength and weakness in the legs (particularly when dantrolene is given by IV injection)
This is not a complete list of dantrolene side effects. Ask your doctor or pharmacist for more information.
Serious side effects have been reported. See "Drug Precautions" section.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:
- baclofen (Lioresal)
- benzodiazepines (drugs used to treat anxiety, panic attacks and other conditions) such as alprazolam (Xanax), chlordiazepoxide (Librium), clobazam (Onfi), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), temazepam (Restoril) and others
- calcium channel blocker medications such as verapamil (Calan, Covera HS, Verelan) and others
- opioids (narcotic pain medicines) such as hydrocodone (in Lortab, in Vicodin), morphine (Avinza, Kadian, MS Contin, others), oxycodone (Oxycontin)
- tricyclic antidepressants such as amitriptyline, amoxapine, desipramine (Norpramin), doxepin, imipramine (Tofranil), nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
- sleep medicines such as eszopiclone (Lunesta), ramelteon (Rozerem), zaleplon (Sonata), zolpidem (Ambien)
- other medicines that cause sedation
- medications for seizures, allergies, colds, or coughs
This is not a complete list of dantrolene drug interactions. Ask your doctor or pharmacist for more information.
Serious side effects may occur including:
- liver injury. The risk of liver injury appears to be greater in females, in patients over 35 years of age, and in patients taking other medication. Your doctor may monitor your liver function while you are taking this medication.
- drowsiness. Dantrolene can cause drowsiness, especially when used with alcohol. Do not drive or operate machinery until you know how this medication affects you.
- cancer or tumors. Some animals treated with dantrolene for prolonged periods at high doses developed tumors and cancers. It is not known if this medication can cause these effects in humans.
- swallowing problems. Dantrolene injection has been reported to cause difficulty swallowing.
- increased risk of sunburn and other sun reactions to skin. Avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Dantrolene may make your skin sensitive to sunlight.
Do not take dantrolene if you:
- are allergic to any component of this medication
- have liver disease
- are unable to maintain balance and upright posture while walking without muscle spasticity
Dantrolene Food Interactions
Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of dantrolene, there are no specific foods that you must exclude from your diet when receiving this medication.
Before taking dantrolene, tell your doctor about all of your medical conditions. Especially tell your doctor if you:
- are allergic to any ingredient in dantrolene
- have liver, heart, rheumatic, or lung disease
- have had seizures or epilepsy
- are pregnant or breastfeeding
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.
Dantrolene and Pregnancy
Tell your doctor if you are pregnant or plan to become pregnant.
The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.
Dantrolene falls into category C. Dantrolene should be given to a pregnant woman only if clearly needed.
Dantrolene and Lactation
Tell your doctor if you are breastfeeding or plan to breastfeed.
Dantrolene has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from dantrolene, a choice should be made whether to stop nursing or to stop use of this medication. The importance of the drug to the mother should be considered.
Take dantrolene exactly as prescribed.
- Dantrolene comes in capsule form, as well as in an injectable form to be given directly into a vein by a healthcare provider.
- Dantrolene capsules are usually taken 3 or 4 times daily.
- Dantrolene can be taken with or without food. If it bothers your stomach try taking it with food.
- If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of dantrolene at the same time.
Take dantrolene exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.
The dantrolene dose your doctor recommends will be based on the following:
- the condition being treated
- other medical conditions you have
- other medications you are taking
- how you respond to this medication
- how you are receiving dantrolene (orally or intravenously)
- your weight
- your age
The maximum recommended dantrolene dose is 100 mg taken 4 times daily.
If you take too much dantrolene call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.
If dantrolene is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.
- Store dantrolene capsules at room temperture between 20° to 25°C (68° to 77°F).
- Keep this and all medications out of the reach of children.
Dantrolene FDA Warning
Dantrolene has a potential for hepatotoxicity, and should not be used in conditions other than those recommended. Symptomatic hepatitis (fatal and non-fatal) has been reported at various dose levels of the drug. The incidence reported in patients taking up to 400 mg/day is much lower than in those taking doses of 800 mg or more per day. Even sporadic short courses of these higher dose levels within a treatment regimen markedly increased the risk of serious hepatic injury. Liver dysfunction as evidenced by blood chemical abnormalities alone (liver enzyme elevations) has been observed in patients exposed to dantrolene for varying periods of time. Overt hepatitis has occurred at varying intervals after initiation of therapy, but has been most frequently observed between the third and twelfth month of therapy. The risk of hepatic injury appears to be greater in females, in patients over 35 years of age, and in patients taking other medication(s) in addition to dantrolene (dantrolene sodium). Spontaneous reports suggest a higher proportion of hepatic events with fatal outcome in elderly patients receiving dantrolene. However, the majority of these cases were complicated with confounding factors such as intercurrent illnesses and/or concomitant potentially hepatotoxic medications. Dantrolene should be used only in conjunction with appropriate monitoring of hepatic function including frequent determination of SGOT or SGPT. If no observable benefit is derived from the administration of dantrolene after a total of 45 days, therapy should be discontinued. The lowest possible effective dose for the individual patient should be prescribed.