Halothone is a general inhalation anesthetic used for the induction and maintenance of general anaesthesia. It provides relatively rapid infuction with little or no excitement. Halothane may not produce sufficient muscle relaxation, so supplemental neuromuscular blocking agents may be required as well. Halothone is diffused across the blood-brain barrier after being inhaled. It then antagonizes NMDA receptors in the brain. This prevents glutamate from binding to NMDA receptors as readily. This prevents calcium from entering the postsynaptic neuron which leads to hyperpolarization. This hyperpolarization of neurons causes an anaesthetic effect.

Halothane NMDA Antagonist Pathway References