Rocuronium (brand names Zemuron, Esmeron) is an aminosteroid non-depolarizing neuromuscular blocker or muscle relaxant used in modern anesthesia to facilitate endotracheal intubation by providing skeletal muscle relaxation, most commonly required for surgery or mechanical ventilation. Rocuronium bromide is a nondepolarizing neuromuscular blocking agent with a rapid to intermediate onset depending on dose and intermediate duration. It acts by competing for cholinergic receptors at the motor end-plate. This action is antagonized by acetylcholinesterase inhibitors, such as neostigmine and edrophonium. Most common adverse reactions are transient hypotension and hypertension.