Which medication is used as a muscle relaxant in the treatment of neuroleptic malignant syndrome?

• A. Dantrolene
• B. Bromocriptine
• C. Cyproheptadine
• D. Lithium

Answer: (A)

Neuroleptic malignant syndrome causes severe muscle rigidity and heat production from dopamine blockade, so reducing skeletal muscle contraction is a primary treatment goal. Dantrolene directly acts on skeletal muscle by inhibiting calcium release from the sarcoplasmic reticulum, which lowers force of contraction and helps relax muscles and reduce hyperthermia. This mechanism targets the core issue of the rigidity and excessive muscle activity seen in NMS, making dantrolene the muscle relaxant of choice in this situation.

Bromocriptine can help by counteracting dopamine blockade as a dopamine agonist, but it’s not a muscle relaxant. Cyproheptadine is used for serotonin syndrome, not NMS. Lithium isn’t used for acute NMS management. Alongside the muscle relaxant, stopping the offending antipsychotic and providing supportive care (cooling, fluids, monitoring labs) are essential.