A. Hyperthermia depolarizing agents

When halothane is used as an anesthetic, administration of succinylcholine has occasionally caused malignant hyperthermia (with muscular rigidity, metabolic acidosis, tachycardia, and hyperpyrexia) in genetically susceptible people. This is treated by rapidly cooling the patient and by administration of dantrolene, which blocks release of Ca2+ from the sarcoplasmic reticulum of muscle cells, thereby reducing heat production and relaxing muscle tone.