Ketamine is a dissociative anesthetic for use in human and veterinary medicine. Pharmacologically, ketamine is classified as an NMDA receptor antagonist. Ketamine has a wide range of effects in humans, including analgesia, anesthesia, hallucinations, arterial hypertension, and bronchodilation. It is primarily used for the induction and maintenance of general anesthesia, usually in combination with some sedative drug. Other uses include sedation in intensive care, analgesia (particularly in emergency medicine), and treatment of bronchospasm. It is also a popular anesthetic in veterinary medicine.