Since the late 90’s law enforcement has warily watched the trend towards increased illicit use of the anesthetic drug, Ketamine (“Special K” or “K”). Chemically related to PCP, Ketamine is a dissociative anesthetic that has human and veterinary applications. Ketamine was first synthesized in 1962 and approved by the Food and Drug Administration (FDA) for use in humans. A unique drug, Ketamine blocks messages traveling between the hypothalamus and the rest of the central nervous system. As a result, a person treated with Ketamine can be awake and but not experience pain caused by surgical procedures conducted on the limbs. Unlike most other anesthetic drugs though, Ketamine has been discovered to have a significant analgesic effect. Ketamine can relieve moderate amounts of pain. It can do this without decreasing heart rate or gastrointestinal tract activity.[1]

For those readers who are interested Ketamine is classified as an antagonist of N-methyl D-aspartate (NMDA) receptors in the dorsal horn of the spinal cord. Ketamine inhibits the binding of excitatory amino acids, such as glutamate to NMDA receptors; this sort of action blocks the transmission of painful stimuli messages. It’s this activity at NMDA receptors that’s thought to be the basis for Ketamine’s analgesic properties. Further, Ketamine seems to inhibit the reuptake of dopamine and serotonin, it also increases levels of circulating norepinephrine. Ketamine is highly fat-soluble and is quickly absorbed following administration. Ketamine metabolism produces a pharmacologically active metabolite called norKetamine.

For Ketamine users found on the street, signs of drug influence somewhat resembles the profile of a PCP abuser. Unlike PCP, its insidious chemical cousin, Ketamine use does not cause hyper-agitated states, psychosis or hallucinations. For DAR trained readers, Ketamine users will display horizontal and vertical nystagmus; pulse will likely be elevated, and the internal clock will be fast. Although Ketamine doesn’t produce the bizarre psychological effects that PCP does, users will often experience a pleasant dream-like feeling while under the influence.[2] At higher doses of the drug, Ketamine users may display a form of gait ataxia that police officers have coined, “moon-walking.” Spatial disturbances and scrambled messages into the central nervous system can cause an array of balance and speech impediments. Chronic Ketamine use can result in addictive behaviors; abuse of the drug is not thought to lead to dependency.

What does the future hold for Ketamine? It is very likely that Ketamine will be more frequently used in community health settings to treat pain. Research is clearly indicating that low doses of Ketamine used on opioid-needing patients reduces pain and lessens the demand for narcotics. This opiate sparing effect is what has pain management and other medical professionals curious. With rapid expansion in the practice of pain management in America, physicians are searching for alternatives to the prescribing of large amounts or high dose opioids. Over the past decade, doctors have loosened the grip on opioids for the treatment of acute and chronic pain. Drugs such as Oxycontin, MS Contin and Vicodin have now become public safety problems as a result of widespread fraud and drug diversion that’s spilled them into the streets. A huge underground demand now exists for those drugs mentioned above as well as for other like-substances such as Percocet (oxycodone), Lortab (hydrocodone), Norco (hydrocodone) and the various fentanyl products.

Will expanded use of Ketamine in the treatment of pain result in a community substance abuse problem similar to what has happened with Oxycontin? It’s unlikely. For the most part, Ketamine will be prescribed by only those physicians who are trained or “boarded” in the practice of pain management. In addition amounts of Ketamine are likely to be found in local hospital emergency rooms where the drug is used in special types of pediatric procedures. Ketamine is not a drug that a family practitioner is likely to prescribe. Ketamine use will probably remain confined to special medical settings. Conditions such as multiple sclerosis, neurpopathic pain and cancer pain are types where Ketamine is proving particularly effective. Continued research may prove that Ketamine can be mixed with drugs to treat other painful conditions as well, this all remains to be seen.

Ketamine is and will continue to be a good veterinary anesthetic. In fact, your own beloved pet dog or cat has probably had a Ketamine “trip” or two as a result of trips taken to the vet’s office for teeth cleaning. At the vet’s Ketamine, (Ketavet) is routinely injected into stressed out animals in an effort to mellow them out enough so that a toothbrush can rubbed over their teeth. Veterinary Ketamine is frequently stolen and diverted to the street. Special K users will take Ketamine containing solution (injectable) and boil it and evaporate off the drug itself. Once reduced to a powder form, users will “snort” the drug (intranasal ingestion). A Special K high will last between 2 & 3 hours.

[1] Hocking, G, Ketamine in chronic pain management; an evidence based review. Anesth Analg 2003; 97(6): 1730-9.
[2] Fine, PG. Low-dose Ketamine in the management of opioid nonresponsive terminal cancer pain. J Pain Symptom Manage 1999; 17(4) 295-300.

Reproduced with permission from The MEDTOX® Journal