Which of the following is used in the treatment of serotonin syndrome?

Dantrolene is utilized in the treatment of serotonin syndrome primarily for its muscle relaxant properties. Serotonin syndrome is characterized by an excess of serotonin in the central nervous system, leading to symptoms like agitation, confusion, neuromuscular abnormalities, and autonomic instability. In severe cases, hyperthermia and muscle rigidity can occur. Dantrolene helps by reversing muscle rigidity and reducing heat production by acting on skeletal muscle, thereby addressing one of the more life-threatening complications of serotonin syndrome.

The other options listed do not address the underlying symptoms of serotonin syndrome effectively. Atropine is primarily used to counteract bradycardia or to reduce secretions and would not alleviate the hyperactive neurological symptoms or muscle rigidity associated with serotonin syndrome. Activated charcoal can be used in cases of overdose, but it does not specifically treat serotonin syndrome and would be suitable only if the patient presents within a specific time frame after ingestion. Digoxin is a cardiac glycoside used in heart failure and certain arrhythmias, with no role in treating serotonin syndrome.