Dantrolene, Oral/Injection

What are other names for this medicine?

Type of medicine: muscle relaxant

Generic and brand names: dantrolene, injection; dantrolene, oral; Dantrium Capsules; Dantrium Injection

What is this medicine used for?

This medicine is taken by mouth to relax certain muscles to relieve problems caused by disease, stroke, or spinal cord injury. It may also be given by injection before or after surgery to prevent a rare but serious condition called malignant hyperthermia (very high fever).

It may be used for other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have:

• an allergy to any medicine
• emphysema, asthma, bronchitis, or other lung disease
• heart disease
• liver disease
• muscle spasms caused by rheumatic disorders

Females of childbearing age: Talk with your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I use it?

Injections of this medicine are given by a healthcare provider.

Check the label on the medicine for directions about your specific dose. Take the capsules exactly as your healthcare provider prescribes. Do not take more or less or take the medicine longer than prescribed.

If you have trouble swallowing, the capsule may be opened and the powder mixed with fruit juice just before you take the medicine.

What if I miss a dose?

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: muscle weakness, drowsiness, fainting, vomiting, diarrhea.

What should I watch out for?

Your healthcare provider needs to see you regularly to check your progress or adjust your dosage. Since this medicine can cause liver damage it is important to have blood tests regularly to see how this medicine affects you. Keep all your appointments. Contact your provider right away if you have signs of liver problems such as yellowish eyes or skin, dark urine, or severe stomach pain.

This medicine increases the effects of alcohol and other medicines that slow down the nervous system. Do not drink alcohol or take other medicines unless your healthcare provider approves.

This medicine may make your skin more sensitive to the sun, which may lead to painful sunburns. While you are taking this medicine, avoid long exposure to the sun. Wear protective clothing, a hat, and sunscreen lotion when you need to be outdoors. Do not use a sunlamp. If you get a severe sunburn, contact your healthcare provider right away.

This medicine may make you drowsy or dizzy. Do not drive or operate machinery unless you are fully alert.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Serious (report these to your healthcare provider right away): yellowish skin or eyes, bloody or dark urine, swollen feet, seizures, slow or shallow breathing, unexplained chills and fever, headache, depression, rash, unusual bleeding or bruising, severe diarrhea,.

Other: Dizziness, drowsiness, weakness, mild diarrhea, nausea, vomiting, blurred vision, trouble sleeping.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• alcohol
• antibiotics such as rifampin (Rifadin), rifabutin (Mycobutin), and clindamycin (Cleocin)
• antiseizure medicines such as phenobarbital, phenytoin (Dilantin), and carbamazepine (Tegretol, Tegretol XL, Carbatrol)
• birth control pills and estrogen products such as conjugated estrogens (Premarin), estradiol (Estrace, Estraderm, Climara, Vivelle), and estropipate (Ogen, Ortho-Est)
• herbal remedies such as valerian, St. John's wort, kava, and gotu kola
• MAO inhibitors such as phenelzine (Nardil), tranylcypromine (Parnate), and selegiline (Eldepryl, Emsam, Zelapar) (Do not take this medicine and an MAO inhibitor within 14 days of each other.)
• narcotic analgesics (painkillers) such as morphine (Oramorph, MS Contin, Roxanol), codeine, oxycodone (OxyContin, Roxicodone), and hydrocodone/acetaminophen (Vicodin, Lortab)
• phenothiazines such as chlorpromazine (Thorazine), fluphenazine (Prolixin), prochlorperazine (Compazine), promethazine (Phenergan), and thioridazine
• sedatives such as phenobarbital, zolpidem (Ambien), triazolam (Halcion), butabarbital (Butisol), eszopiclone (Lunesta), and zaleplon (Sonata)
• tranquilizers such as diazepam (Valium), meprobamate (Equanil), chlordiazepoxide (Librium), alprazolam (Xanax), and lorazepam (Ativan)
• verapamil (Calan, Isoptin, Verelan)

Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

If you have the capsules, store them at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light. Do not freeze.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Keep all medicines out of the reach of children.

Do not share medicines with other people.