Dantrolene for Pain
People who have exercise-induced muscle pain may receive dantrolene sodium (Dantrium®). However, this is an "off-label," or unapproved, use of the medication. Dantrolene is a type of prescription muscle relaxant that works directly on the muscle. It comes in the form of capsules or an injection that is given slowly into a vein.
The approved uses of dantrolene include controlling muscle spasms and stiffness (spasticity) associated with certain medical conditions, such as a stroke, spinal cord injury, or multiple sclerosis. It is also approved to prevent or treat a rare condition known as malignant hyperthermia, which is a severe and potentially life-threatening reaction to general anesthesia that causes high fever and muscle rigidity.
(Click What Is Dantrolene Used For? to learn more about using this drug to treat pain or other off-label uses. This article also describes how it works and whether it is safe for use in children.)