dantrolene sodium /dan″trəlēn/ , a skeletal muscle relaxant that acts directly on the skeletal muscle to prevent the release of calcium from the sarcoplasmic reticulum that is needed for muscle contraction. ▪ INDICATIONS: It is prescribed in the treatment of muscle spasticity resulting from injury to the spinal cord or cerebrum when the person is immobile and flaccid limbs are preferable to spastic limbs. It is not indicated in treatment of spasm from rheumatic disorders. It is used intravenously for the management of malignant hyperthermia. ▪ CONTRAINDICATIONS: Dantrolene should not be used when spastic muscles are needed to maintain posture or balance. Liver dysfunction or known hypersensitivity to this drug also prohibits its use. ▪ ADVERSE EFFECTS: The most serious adverse reaction is potentially fatal hepatotoxicity. Common reactions include confusion, drowsiness, diarrhea, dizziness, fatigue, and muscular weakness. Side effects may continue for several days.
