In cases of chronic spasticity: Dantrolene is used to manage the symptoms of muscle stiffness caused by upper motor neuron disorders such as spinal cord injury, stroke, cerebral palsy, or multiple sclerosis. It is especially helpful for patients whose rehabilitation progress has been slowed due to spasticity-related complications. The medication is most suitable for patients with potentially reversible spasticity, where reducing muscle stiffness can help restore remaining functional abilities. However, Dantrolene is not used for treating muscle spasms caused by rheumatic conditions. In some cases, patients may experience mild but meaningful improvement in spasticity with this treatment, and such changes should be reported by the patient. Temporarily stopping Dantrolene for 2 to 4 days may lead to a worsening of symptoms, which can help confirm its effectiveness.

A decision to maintain long-term treatment with Dantrolene is considered appropriate if adding the medication to the patient’s treatment plan:

• leads to a noticeable decrease in painful and/or disabling muscle spasticity, such as clonus, or
• allows a meaningful reduction in the level and/or effort of nursing care needed, or
• eliminates any troublesome symptoms of spasticity that the patient personally finds significant

In Malignant Hyperthermia: Oral Dantrolene is indicated for preoperative use to prevent or reduce the onset of symptoms of malignant hyperthermia in patients who are known or strongly suspected to be susceptible and who require anesthesia and/or surgery. It should also be given after a malignant hyperthermia crisis to help prevent the recurrence of symptoms.

Dantrolene induces muscle relaxation by acting directly on skeletal muscle, at a point beyond the myoneural junction, thereby altering the muscle’s contractile response. In skeletal muscle, it disrupts the excitation–contraction coupling process, most likely by inhibiting the release of calcium (Ca) from the sarcoplasmic reticulum.

For Use in Chronic Spasticity:

• Adults: The following gradual titration schedule is suggested. Some patients will not respond until higher daily dosage is achieved. Each dosage level should be maintained for seven days to determine the patient's response. If no further benefit is observed at the next higher dose, dosage should be decreased to the previous lower dose.
• Starting dose is 25 mg twice per day and it can be increased to 25-50 mg per day per week. Maximum accepted dosage is 400 mg per day.
• Paediatric Patients: The following gradual titration schedule is suggested. Some patients will not respond until higher daily dosage is achieved. Each dosage level should be maintained for seven days to determine the patient's response. If no further benefit is observed at the next higher dose, dosage should be decreased to the previous lower dose.
• 0.5 mg/kg once daily for seven days, then 0.5 mg/kg 3 times for 7 days, 1 mg/kg 3 times for 7 days, 2 mg/kg 3 times a day, Therapy with a dose 4 times daily may be necessary for some individuals.

For Malignant Hyperthermia

• Preoperatively: Administer 4 to 8 mg/kg/day of oral Dantrolene in 3 or 4 divided doses for one or two days prior to surgery, with the last dose being given approximately 3 to 4 hours before scheduled surgery with a minimum of water
• Post Crisis Follow-up: Oral Dantrolene should also be administered following a malignant hyperthermia crisis, in doses of 4 to 8 mg/kg per day in four divided doses, for a one to three day period to prevent recurrence of the manifestations of malignant hyperthermia.

Dantrolene treatment may lead to drowsiness, and when combined with CNS depressants such as sedatives or tranquilizers, this effect may become more pronounced. Hepatotoxicity has been observed more frequently in women over 35 years of age who are also undergoing estrogen therapy.

Active liver disease, including conditions such as hepatitis and cirrhosis.

The most common side effects of Dantrolene include drowsiness, dizziness, muscle weakness, general discomfort, fatigue, and diarrhea. These effects are usually temporary and occur early in treatment. They can often be minimized by starting with a low dose and gradually increasing it until the optimal dose is reached. Diarrhea may become severe and may require temporary discontinuation of therapy. If diarrhea returns after restarting Dantrolene, the treatment should likely be stopped permanently.

Pregnancy Category C: Dantrolene capsules should be administered during pregnancy only when the expected benefit outweighs the potential risk to the fetus. Dantrolene is not recommended for use in breastfeeding mothers.

Because of the risk of liver damage with long-term use of Dantrolene, treatment should be discontinued if no clear benefit is observed within 45 days. Patients should be warned not to drive vehicles or engage in hazardous work while taking this medication. Caution is also advised when using tranquilizers at the same time. Dantrolene may potentially cause photosensitivity reactions, so patients should avoid excessive exposure to sunlight during therapy. It is important to note that both fatal and non-fatal liver disorders of idiosyncratic or hypersensitivity origin may occur with Dantrolene use. Before starting treatment, liver function tests (SGOT, SGPT, alkaline phosphatase, total bilirubin) should be performed to establish a baseline or to detect any existing liver disease. These liver function tests should be repeated at regular intervals during therapy. In some patients, test results may return to normal despite continued treatment, while in others they may not. If signs of hepatitis, jaundice, or abnormal liver function tests occur, Dantrolene should be stopped. When detected early and if caused by the drug, liver abnormalities usually return to normal after discontinuation. In a few cases, Dantrolene has been restarted in patients who previously showed liver injury, but this should only be done when the drug is clearly necessary, after complete resolution of symptoms and laboratory abnormalities. Such patients should be hospitalized, and therapy should be restarted at very low doses with gradual increases. Frequent laboratory monitoring is essential, and the drug must be stopped immediately if any signs of liver recurrence appear. Dantrolene should be used with extra caution in women and in patients over 35 years of age, as these groups appear to have a higher risk of potentially fatal liver disease.

It should also be used carefully in patients with impaired lung function, severe heart disease due to myocardial conditions, and those with a history of liver disease or liver dysfunction.

Use in Paediatric Patients: The long-term safety of Dantrolene in children under 5 years of age has not yet been established. Since some adverse effects may only become evident after many years, careful evaluation of the benefit versus risk is especially important when considering long-term use in paediatric patients.

Centrally acting Skeletal Muscle Relaxants

Store in a cool, dry place and protect from light. Store in a cool, dry place and protect from light.