Dantrium (generic: dantrolene) is a prescription medication used to relieve spasms and increased muscle tone caused by multiple sclerosis, stroke, or brain or spinal injury. Dantrium belongs to a group of drugs called muscle relaxants. Dantrium causes muscle relaxation by interfering with calcium release within the muscle.

This medication comes in the form of a capsule and a liquid for injection. The capsule is usually taken by mouth 3 or 4 times daily. The injection is given directly into a vein (IV) by a healthcare provider.

Common side effects include diarrhea, drowsiness, and dizziness. Do not drive or operate machinery until you know how it affects you. It is best to avoid alcohol while taking Dantrium.