How does dantrolene work?
Dantrolene works by stopping some electrical impulses travelling within muscles, thereby preventing muscle contractions. This contrasts with most other spasticity drugs that work by preventing or inhibiting the way the brain and spinal cord communicate through the nerves with the rest of the body.
How do I take dantrolene?
Dantrolene sodium is taken orally as tablets. Dosage varies but should not exceed 400mg per day.
Side effects and contraindications
Side effects include drowsiness, dizziness, weakness and fatigue. All of these may be temporary. Another side effect you may experience is diarrhoea, which can be severe. Dantrolene should not be taken by people with a history of liver dysfunction, or by pregnant or breastfeeding women.
Liver function tests should be carried out before starting and frequently during treatment as there is a risk of liver damage (known as hepatotoxicity).
Last updated: January 2018
Last reviewed: January 2018
This page will be reviewed within three years
Spasticity triggers tool
Find out more about identifying potential trigger factors and how to manage them.
Spasticity and spasms
Spasticity is a symptom of MS where the muscles feel stiff, heavy and difficult to move. A spasm is a sudden stiffening of a muscle.
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