Editing Cathinone (section)

===Pharmacokinetics===
Khat leaves are removed from the plant stalk and are kept in a ball in the cheek and chewed. Chewing releases juices from the leaves, which include the alkaloid cathinone. The absorption of cathinone has two phases: one in the [[buccal mucosa]] and one in the [[stomach]] and [[small intestine]].<ref name="Wilder"/> The stomach and small intestine are very important in the absorption of ingested alkaloids.<ref name="Wilder"/> At approximately 2.3 hours after chewing khat leaves, the maximum concentration of cathinone in blood plasma is reached. The mean residence time is 5.2&nbsp;±&nbsp;3.4 hours.<ref name="Wilder"/> The elimination half-life of cathinone is 1.5&nbsp;±&nbsp;0.8 hours.<ref name="Wilder"/> A two-compartment model for absorption and elimination best describes this data. However, at most, only 7% of the ingested cathinone is recovered in the urine.<ref name="Wilder"/> This indicates that the cathinone is being broken down in the body. Cathinone has been shown to selectively metabolize into R,S-(-)-norephedrine and cathine. The reduction of the [[ketone]] group in cathinone will produce cathine. This reduction is catalyzed by enzymes in the liver. The spontaneous breakdown of cathinone is the reason it must be chewed fresh after cultivation.<ref name="Wilder"/>