Brand Name(s): Dantrium

Generic Name Dantrolene

What are dantrolene capsules?

DANTROLENE (Dantrium®) is a muscle relaxant. It helps to relax muscles, relieving spasms and stiffness of muscles in conditions such as multiple sclerosis, cerebral palsy, stroke, or injury to the spine. Dantrolene can also help prevent and treat a condition called malignant hyperthermia, which may occur after surgery or anesthesia. Generic dantrolene capsules are available.

What should my health care professional know before I take dantrolene?

They need to know if you have any of these conditions:

• heart disease
• liver disease
• lung disease
• muscle, or neuromuscular disease (incluing multiple sclerosis)
• an unusual or allergic reaction to dantrolene, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I take this medicine?

Take dantrolene capsules by mouth. Follow the directions on the prescription label. Swallow the capsules with a drink of water. If you find it difficult to swallow the capsules, empty the contents of the capsules into juice or liquid; stir well and drink at once. Take your doses at regular intervals. Do not take your medicine more often than directed.

What if I miss a dose?

If you miss a dose, take it as soon as you can if you remember within an hour. If it is almost time for your next dose, take only the next dose. Do not take double or extra doses.

What drug(s) may interact with dantrolene?

• alcohol
• female hormones, including contraceptive or birth control pills
• medicines for angina or high blood pressure
• medicines for anxiety or sleeping problems, such as diazepam or temazepam
• medicines for mental depression
• medicines for mental problems or psychotic disturbances
• medicines for pain

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What side effects may I notice from taking dantrolene?

Serious side effects are more likely to occur after long-term treatment with dantrolene; they include:

• dark yellow or brown urine
• black, or tarry stools
• chest pain
• difficulty breathing
• fever
• pain or changes in skin color
• pain or difficulty passing urine
• seizures (convulsions)
• skin rash
• stomach pain, nausea, vomiting
• swelling of feet or legs
• yellowing of eyes or skin

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):

• blurred vision
• depression
• diarrhea, or constipation
• drowsiness or dizziness
• increased sensitivity to sunlight
• loss of appetite
• nervousness or confusion
• passing urine more often
• slurred speech
• trouble sleeping (insomnia)
• weakness or tiredness

What should I watch for while taking dantrolene?

Visit your prescriber or health care professional for regular checks on your progress.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how dantrolene affects you. To reduce the risk of dizzy or fainting spells, do not sit or stand up quickly, especially if you are an older patient. Alcohol can make you more drowsy; avoid alcoholic drinks.

Dantrolene may make your skin sensitive to sunlight (UV). Keep out of the sun, or wear protective clothing outdoors and use a sunscreen. Do not use sun lamps or sun tanning beds or booths.

Where can I keep my medicine?

Keep out of the reach of children in a container that small children cannot open.

Store at room temperature below 40 °C (104 °F). Throw away any unsed medicine after the expiration date.