Dantrium is the only drug indicated for and proven effective in the treatment of spasticity in all of the following disorders:
spinal cord injury
Dantrium capsules are indicated in controlling the manifestations of clinical spasticity resulting from upper motor neuron disorders (i.e., spinal cord injury, stroke, cerebral palsy, or multiple sclerosis).
Dantrolene sodium lowers the intracellular calcium concentration in skeletal muscle by a mechanism which is not fully understood. This reduces the sensitivity of the muscles to nerve signals. As a result, the muscles can relax and spasticity is reduced.
Dantrolene sodium is used as a muscle relaxant in conditions where there is chronic, severe spasticity.
For the individual patient, the lowest dose compatible with optimal response is recommended.
A recommended dosage increment scale is shown below:-
First: One 25mg capsule daily
Second: One 25mg capsule twice daily
Third: Two 25mg capsules twice daily
Fourth: Two 25mg capsules three times daily
Fifth: Three 25mg capsules three times daily
Sixth: Three 25mg capsules four times daily
Seventh: One 100mg capsule four times daily
Each dosage level should be maintained for seven days in order to determine the patient's response. Therapy with a dose four times daily may offer maximum benefit to some patients. The maximum daily dose should not exceed 400mg. In view of the potential for hepatoxicity in long term use, if no observable benefit is derived from the administration of Dantrium after a total of 45 days, therapy should be discontinued.
A similar dosage scheme should be used with the elderly.
Dantrium is not recommended for use in children.
The most frequently reported unwanted effects associated with the use of Dantrium have been drowsiness, dizziness, weakness, general malaise, fatigue and diarrhoea. These effects are generally transient, occur early in treatment, and can often be obviated by careful determination and regulation of the dosage. Diarrhoea may be severe, and may necessitate temporary withdrawal of Dantrium. If diarrhoea recurs upon re-introduction of Dantrium, then Dantrium therapy should probably be withdrawn permanently. Other frequent side effects include anorexia, nausea, headache and skin rash. Less frequent side effects include constipation, dysphagia, speech disturbance, visual disturbance, confusion, nervousness, depression, seizures, increased urinary frequency, and insomnia. Rare reports include tachycardia, erratic blood pressure, dyspnoea, haematuria, crystalluria (unconfirmed reports), urinary incontinence, and urinary retention. Pleural effusion and/or pericarditis in patients using Dantrium have been rarely reported. Chills and fever have occasionally been reported.
Dantrium has a potential for hepatotoxicity. Symptomatic hepatitis (fatal and non-fatal) has been reported at various dose levels although the incidence is greater in patients taking more than 400 mg/day. Liver dysfunction as evidenced by blood chemical abnormalities alone (liver enzyme elevation) has been observed in patients exposed to Dantrium for varying periods of time.
Overt hepatitis has occurred at varying intervals after initiation of therapy, but has most frequently been observed between the second and twelfth month of treatment. The risk of hepatic injury appears to be greater in females, in patients over 30 years old and in patients taking concomitant medication. There is some evidence that hepatic injury is more likely in patients using concomitant oral oestrogen.