The more active enantiomer, esketamine (S-ketamine), is also available for medical use under the brand name Ketanest S, while the less active enantiomer, arketamine (R-ketamine), has never been marketed as an enantiopure drug for clinical use. While S-ketamine is more effective as an analgesic and anesthetic through NMDA receptor antagonism, R-ketamine produces longer-lasting effects as an antidepressant. The optical rotation of a given enantiomer of ketamine can vary between its salts and free base form. The free base form of (S)‑ketamine exhibits dextrorotation and is therefore labelled (S)‑(+)‑ketamine. However, its hydrochloride salt shows levorotation and is thus labelled (S)‑(−)‑ketamine hydrochloride. Detection
Ketamine may be quantitated in blood or plasma to confirm a diagnosis of poisoning in hospitalized people, provide evidence in an impaired driving arrest, or to assist in a medicolegal death investigation. Blood or plasma ketamine concentrations are usually in a range of 0.5–5.0 mg/L in persons receiving the drug therapeutically (during general anesthesia), 1–2 mg/L in those arrested for impaired driving and 3–20 mg/L in victims of acute fatal overdosage. Urine is often the preferred specimen for routine drug use monitoring purposes. The presence of norketamine, a pharmacologically active metabolite, is useful for confirmation of ketamine ingestion. History
Ketamine was first synthesized in 1962 by Calvin L. Stevens, a professor of chemistry at Wayne State University and a Parke-Davis consultant. It was known by the developmental code name CI-581. After promising preclinical research in animals, ketamine was tested in human prisoners in 1964.
Overhydrated hereditary stomatocytosis
Dehydrated hereditary stomatocytosis (hereditary xerocytosis; hereditary hyperphosphatidylcholine haemolytic anaemia)
Dehydrated hereditary stomatocytosis with perinatal edema and/or pseudohyperkalemia
Cryohydrocytosis
Blackburn variant
Familial pseudohyperkalaemia (not associated with hemolytic anemia)There are other families that do not fall neatly into any of these classifications.Stomatocytosis is also found as a hereditary disease in Alaskan malamute and miniature schnauzer dogs. Treatment
At present there is no specific treatment. Many patients with haemolytic anaemia take folic acid (vitamin B9) since the greater turnover of cells consumes this vitamin. During crises transfusion may be required. Clotting problems can occur for which anticoagulation may be needed. Unlike hereditary spherocytosis, splenectomy is contraindicated. References
Further reading


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