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Dantrium Capsules

Last reviewed on RxList: 12/29/2016
Dantrium Capsules Side Effects Center

Last reviewed on RxList 1/7/2016

Dantrium (dantrolene sodium) is a muscle relaxant used to treat muscle spasticity (stiffness and spasms) caused by conditions such as a spinal cord injury, stroke, cerebral palsy, or multiple sclerosis. Dantrium is also used to prevent muscle stiffness and spasms caused by malignant hyperthermia (a rapid rise in body temperature) that can occur during surgery with certain types of anesthesia. Dantrium is available in generic form. Common side effects of Dantrium include drowsiness, dizziness, weakness, tiredness, nausea, vomiting, stomach pain, and diarrhea as the body adjusts to this medication, which usually lessens after several days. Other side effects of Dantrium include headache, constipation, slurred speech, drooling, problems with balance or walking, headache, confusion, vision problems, sleep problems (insomnia), or urinating more than usual.

The usual adult dosage schedule for Dantrium is 25 mg once daily for seven days, then 25 mg three times daily for seven days, then 50 mg three times daily for seven days, and up to 100 mg three times daily. Dantrium may interact with cold or allergy medicine, sedatives, narcotics, sleeping pills, medicine for seizures, depression or anxiety, other muscle relaxers, birth control pills and other hormones, or heart or blood pressure medications. Tell your doctor all medications and supplements you use. During pregnancy, Dantrium should be used only when prescribed. This drug passes into breast milk and could have undesirable effects on a nursing infant. Breastfeeding is not recommended while using this drug.

Our Dantrium (dantrolene sodium) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Dantrium Capsules Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • severe diarrhea or constipation;
  • weak or shallow breathing;
  • pale skin, easy bruising or bleeding;
  • trouble swallowing, especially if it causes choking;
  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
  • black, bloody, or tarry stools;
  • coughing up blood or vomit that looks like coffee grounds;
  • seizure (black-out or convulsions); or
  • urinating less than usual or not at all.

Less serious side effects may include:

  • drowsiness, dizziness, weakness, tired feeling;
  • mild diarrhea or constipation;
  • mild nausea, vomiting, stomach pain;
  • problems with speech, balance, or walking;
  • headache, confusion, vision problems;
  • sleep problems (insomnia);
  • sweating, drooling; or
  • urinating more than usual.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Dantrium Capsules (Dantrolene Sodium Capsules)

Dantrium Capsules Professional Information


The most frequently occurring side effects of Dantrium have been drowsiness, dizziness, weakness, general malaise, fatigue, and diarrhea. These are generally transient, occurring early in treatment, and can often be obviated by beginning with a low dose and increasing dosage gradually until an optimal regimen is established. Diarrhea may be severe and may necessitate temporary withdrawal of Dantrium therapy. If diarrhea recurs upon readministration of Dantrium, therapy should probably be withdrawn permanently. Other less frequent side effects, listed according to system, are:

Gastrointestinal: Constipation, rarely progressing to signs of intestinal obstruction, GI bleeding, anorexia, swallowing difficulty, gastric irritation, abdominal cramps, nausea and/or vomiting.

Hepatobiliary: Hepatitis (see WARNINGS).

Neurologic: Speech disturbance, seizure, headache, light-headedness, visual disturbance, diplopia, alteration of taste, insomnia, drooling.

Cardiovascular: Tachycardia, erratic blood pressure, phlebitis, heart failure.

Hematologic: Aplastic anemia, anemia, leukopenia, lymphocytic lymphoma, thrombocytopenia.

Psychiatric: Mental depression, mental confusion, increased nervousness.

Urogenital: Increased urinary frequency, crystalluria, hematuria, difficult erection, urinary incontinence and/or nocturia, difficult urination and/or urinary retention.

Integumentary: Abnormal hair growth, acne-like rash, pruritus, urticaria, eczematoid eruption, sweating.

Musculoskeletal: Myalgia, backache.

Respiratory: Feeling of suffocation, respiratory depression.

Special Senses: Excessive tearing.

Hypersensitivity: Pleural effusion with pericarditis, pleural effusion with associated eosinophilia, anaphylaxis.

Other: Chills and fever.

The published literature has included some reports of Dantrium use in patients with Neuroleptic Malignant Syndrome (NMS). Dantrium capsules are not indicated for the treatment of NMS and patients may expire despite treatment with Dantrium capsules.

For medical advice about adverse reactions contact your medical professional. To report SUSPECTED ADVERSE REACTIONS, contact JHP at 1-866-923-2547 or MEDWATCH at 1�800-FDA-1088 (1-800-332-1088) or

Drug Abuse And Dependence

Drug abuse and dependency potential has not been evaluated in human or animal studies.

Read the entire FDA prescribing information for Dantrium Capsules (Dantrolene Sodium Capsules)

Related Resources for Dantrium Capsules

Read the Dantrium Capsules User Reviews »

© Dantrium Capsules Patient Information is supplied by Cerner Multum, Inc. and Dantrium Capsules Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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