DANTROLENE (Systemic)
Some commonly used brand names are:
In the U.S.?
- Dantrium
- Dantrium Intravenous
In Canada?
- Dantrium
- Dantrium Intravenous
Category
- Antispastic
- Duchennemuscular dystrophy therapy adjunct
- Malignant hyperthermiatherapy adjunct
- Muscle phosphorylase deficiencytherapy adjunct
- Neuroleptic malignant syndrometherapy adjunct
Description
Dantrolene (DAN-troe-leen) is used to help relax certain muscles in your body. Itrelieves the spasms, cramping, and tightness of muscles caused by certainmedical problems such as multiple sclerosis (MS), cerebral palsy, stroke,or injury to the spine. Dantrolene does not cure these problems, but it mayallow other treatment, such as physical therapy, to be more helpful in improvingyour condition. Dantrolene acts directly on the muscles to produce its relaxanteffects.
Dantrolene is also used to prevent or treat a medical problem called malignanthyperthermia that may occur in some people during or following surgery oranesthesia. Malignant hyperthermia consists of a group of symptoms includingvery high fever, fast and irregular heartbeat, and breathing problems. Itis believed that the tendency to develop malignant hyperthermia is inherited.
Dantrolene has been shown to cause cancer and noncancerous tumors in someanimals (but not in others) when given in large doses for a long time. Itis not known whether long-term use of dantrolene causes cancer or tumors inhumans. Before taking this medicine, be sure that you have discussed thiswith your doctor.
This medicine is available only with your doctor's prescription, in thefollowing dosage forms:
Oral- Capsules (U.S. and Canada)
Parenteral- Injection (U.S. and Canada)
Before Using This Medicine
In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For dantrolene, thefollowing should be considered:
Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to dantrolene. Also tell your health care professional ifyou are allergic to any other substances, such as foods, preservatives, ordyes.
Pregnancy?Dantrolene has not been shown to cause birth defectsor other problems in humans.
Breast-feeding?Use of dantrolene is not recommended during breast-feeding.
Children?This medicine has been tested in children 5 yearsof age and older and has not been shown to cause different side effects orproblems than it does in adults.
Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults or if they cause different side effectsor problems in older people. There is no specific information comparing useof dantrolene in the elderly with use in other age groups.
Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingdantrolene, it is especially important that your health care professionalknow if you are taking any of the following:
- Acetaminophen (e.g., Tylenol) (with long-term, high-dose use) or
- Amiodarone (e.g., Cordarone) or
- Anabolic steroids (dromostanolone [e.g., Drolban], ethylestrenol[e.g., Maxibolin], nandrolone [e.g., Anabolin], oxandrolone [e.g., Anavar],oxymetholone [e.g., Anadrol], stanozolol [e.g., Winstrol]) or
- Androgens (male hormones) or
- Anti-infectives by mouth or by injection (medicine for infection)or
- Antithyroid agents (medicine for overactive thyroid) or
- Carbamazepine (e.g., Tegretol) or
- Carmustine (e.g., BiCNU) or
- Central nervous system (CNS) depressants (medicine that causes drowsiness)or
- Chloroquine (e.g., Aralen) or
- Daunorubicin (e.g., Cerubidine) or
- Disulfiram (e.g., Antabuse) or
- Divalproex (e.g., Depakote) or
- Estrogens (female hormones) or
- Etretinate (e.g., Tegison) or
- Gold salts (medicine for arthritis) or
- Hydroxychloroquine (e.g., Plaquenil) or
- Mercaptopurine (e.g., Purinethol) or
- Methotrexate (e.g., Mexate) or
- Methyldopa (e.g., Aldomet) or
- Naltrexone (e.g., Trexan) (with long-term, high-dose use) or
- Oral contraceptives (birth control pills) containing estrogen or
- Phenothiazines (acetophenazine [e.g., Tindal], chlorpromazine [e.g.,Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil],perphenazine [e.g., Trilafon], prochlorperazine [e.g., Compazine], promazine[e.g., Sparine], promethazine [e.g., Phenergan], thioridazine [e.g., Mellaril],trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin], trimeprazine[e.g., Temaril]) or
- Phenytoin (e.g., Dilantin) or
- Plicamycin (e.g., Mithracin) or
- Tricyclic antidepressants (medicine for depression) (amitriptyline[e.g., Elavil], amoxapine [e.g., Asendin], clomipramine [e.g., Anafranil],desipramine [e.g., Pertofrane], doxepin [e.g., Sinequan], imipramine [e.g.,Tofranil], nortriptyline [e.g., Aventyl], protriptyline [e.g., Vivactil],trimipramine [e.g., Surmontil]) or
- Valproic acid (e.g., Depakene)?The chance of side effects maybe increased
Other medical problems?The presence of other medicalproblems may affect the use of dantrolene. Make sure you tell your doctorif you have any other medical problems, especially:
- Emphysema, asthma, bronchitis, or other chronic lung disease or
- Heart disease or
- Liver disease, such as hepatitis or cirrhosis (or history of)?Thechance of serious side effects may be increased
Proper Use of This Medicine
If you areunable to swallow the capsules, you may empty the number of capsules neededfor one dose into a small amount of fruit juice or other liquid. Stir gentlyto mix the powder with the liquid before drinking. Drink the medicine rightaway. Rinse the glass with a little more liquid and drink that also to makesure that you have taken all of the medicine.
Dantrolene may be taken with or without food or on a full or empty stomach.However, if your doctor tells you to take the medicine a certain way, takeit exactly as directed.
Take this medicine only as directed by your doctor. Do not take more of it and do not take it more often than your doctorordered. Dantrolene may cause liver damage or other unwanted effects if toomuch is taken.
Dosing?The dose of dantrolene will be different fordifferent patients. Follow your doctor's orders or thedirections on the label. The following information includes only theaverage doses of dantrolene. If your dose is different,do not change it unless your doctor tells you to do so:
The number of capsules that you take depends on the strength of the medicine.Also, the number of doses you take each day, the time allowed between doses,and the length of time you take the medicine depend on the medical problemfor which you are taking dantrolene.
- For oral dosage form (capsules):
- For prevention or treatment of a malignant hyperthermic crisis:
- Adults?Dose is based on body weight and must be determinedby your doctor. The usual dose is 4 to 8 milligrams (mg) per kilogram (kg)(1.8 to 3.6 mg per pound) of body weight. The doctor will instruct you exactlywhen and how often to take your medicine.
- To relieve spasms:
- Adults?To start, 25 mg once a day. The doctor may increaseyour dose as needed and tolerated. However, the dose is usually not more than100 mg four times a day.
- Children?Dose is based on body weight and must be determinedby your doctor. To start, the dose is usually 0.5 mg per kg (0.23 mg per pound)of body weight twice a day. The doctor may increase the dose as needed andtolerated. However, the dose is usually not more than 3 mg per kg or 100 mgfour times a day.
- For injection dosage form:
- For prevention or treatment of a malignant hyperthermia crisis:
- Adults, teenagers, and children?Dose is based on body weightand must be determined by your doctor.
Missed dose?If you miss a dose of this medicine and rememberwithin an hour or so of the missed dose, take it right away. Then go backto your regular dosing schedule. But if you do not remember until later, skipthe missed dose and go back to your regular dosing schedule. Do not doubledoses.
Storage?To store this medicine:
- Keep out of the reach of children.
- Store away from heat and direct light.
- Do not store this medicine in the bathroom, near the kitchen sink,or in other damp places. Heat or moisture may cause the medicine to breakdown.
- Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.
Precautions While Using This Medicine
If youwill be taking dantrolene for a long time (for example, for several monthsat a time), your doctor should check your progress at regular visits. It maybe necessary to have certain blood tests to check for unwanted effects whileyou are taking dantrolene.
This medicine will add to the effects of alcohol and other CNS depressants(medicines that slow down the nervous system, possibly causing drowsiness).Some examples of CNS depressants are antihistamines or medicine for hay fever,other allergies, or colds; sedatives, tranquilizers, or sleeping medicine;prescription pain medicine or narcotics; barbiturates; medicine for seizures;other muscle relaxants; or anesthetics, including some dental anesthetics.Therefore, do not drink alcoholic beverages, and checkwith your doctor before taking any of the medicines listed above, while youare using this medicine.
This medicine may cause drowsiness, dizziness or lightheadedness, visionproblems, or muscle weakness in some people. Make sureyou know how you react to this medicine before you drive, use machines, ordo anything else that could be dangerous if you are dizzy or are not alert,well-coordinated, and able to see well.
Side Effects of This Medicine
Along with its needed effects, a medicine may cause some unwanted effects.Although not all of these side effects may occur, if they do occur they mayneed medical attention. Serious side effects are very rare when dantroleneis taken for a short time (for example, when it is used for a few days before,during, or after surgery or anesthesia to prevent or treat malignant hyperthermia).However, serious side effects may occur, especially when the medicine is takenfor a long time.
Also, check with your doctoras soon as possible if any of the following side effects occur:
Other side effects may occur that usually do not need medical attention.These side effects may go away during treatment as your body adjusts to themedicine. However, check with your doctor if any of the following side effectscontinue or are bothersome:
Otherside effects not listed above may also occur in some patients. If you noticeany other effects, check with your doctor.
Revised: 05/10/1993
