Ketamine is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist which was developed in the 1960s for medical use and is now used widely throughout the world for anesthesia and pain relief in both humans and animals, particularly horses. Ketamine is a potent pain killer and is particularly useful for children undergoing agonizing procedures such as treatment of burns. As a dissociative drug, it is used recreationally and as a "date rape" drug. Ketamine can be detected in urine up to 14 days after the last use and up to 24 hours in blood.