The controversial, highly regulated drug Ketamine due to its black market presence and human substance abuse, is known as "Special K".
Ketamine which belongs to the dissociative anaesthetics class possesses three main mechanisms of action:
1) Antagonist at glutamate NMDA receptors
2) Antagonist at muscarinic receptors
3) Agonist at opioid receptors, which is responsible for providing analgesic properties to this potent drug.
Ketamine's ability to induce anaesthesia is by its ability to form a 'functional' dissociation between the thalamus and the cerebral cortex (in the brain).
Side effects resemble sympathetic nervous system stimulation which includes: Increased heart rate, cardiac output, myocardial consumption and blood pressure. Fortunately, Ketamine rarely induces respiratory depression.
As Ketamine is a poor muscle relaxant, the drug is usually used in combination with Diazepam (Valium) which is a sedative and helps to reduce muscle tone. Ketamine is commonly used to anaesthetise horses and is also used in mixed-solutions for feline anaesthesia.