Khat leaf

Kalix P, Braenden O Pharmacological aspects of the chewing of khat leaves. Pharmacol Rev 37 149-164, 1985... 

Chewing leaves of the khat shrub is practiced in parts of East Africa and the Arabian peninsula (Kalix 1988 Widler et al. 1994). Some estimate daily use at 5 million portions. Use in the West is less common, but has increased somewhat. More common in the United States has been use of the synthetic drug methcathinone (or "cat"), which is derived from khat alkaloids. Only the fresh khat leaves are pharmacologically active, so for some time use was limited to local areas that grew the plant. However, with air transportation, use has spread with emigrants in Europe and the United States. Because of its pharmacological similarities to amphetamine and its addictive properties, khat has been listed on Schedule I of the United Nations Convention on Psychotropic Substances. 

In its natural form, fresh khat leaves are chewed because the drug is perishable. Young leaves from the tip of the branch are more potent. While the leaves are chewed, the juices are swallowed and the residue is rejected. During a session, one may ingest 100 to 200 grams of leaves. 

Halket JM, Karasu Z, Murray-Lyon IM. (1995). Plasma cathinone levels following chewing khat leaves (Catha edulis Forsk.). J Ethnopharmacol. 49(2) 111-13. 

Kalix P. (1980). A constituent of khat leaves with amphetamine-like releasing properties. EurJ Pharmacol. 68(2) 213-15. 

Kalix P. (1981). Cathinone, an alkaloid from khat leaves with an amphetamine-like releasing effect. Psychopharmacology (Berlin). 74(3) 269-70. 

After chewing khat leaves, it can take up to two hours to achieve peak levels of cathinone. The half-life is about 4.5 hours. 

Khat leaves left unrefrigerated beyond 48 hours contain only cathine, which explains users preference for fresh leaves. The young leaves and buds are chewed as a mild stimulant the chewing produces a strong... 

Fresh khat leaves are most often prepared for shipment in bouquet-sized bundles, wrapped in plastic bags or banana leaves, then tied together. The bundles are sprayed with water to keep the leaves fresh and moist, especially important when the leaves are shipped outside of the country of origin. 

Khat leaves are typically chewed like tobacco. Users fill the mouth with fresh leaves that they chew to release the active ingredients. Khat is also sold as dried or crushed leaves, frozen leaves, or in powdered form. 

Another method of ingesting khat is by chewing a paste made of khat leaves, water, and sugar or honey, sometimes flavored with herbs. A tea made from the flowers of the khat plant— flower of paradise in Yemen—is considered restorative. In addition, the leaves are sometimes added to plain tea, or smoked in combination with tobacco. Ethiopians often drink a juice extract made from khat leaves. 

In one study on a group of 80 healthy volunteers, researchers found that during a three-hour period of chewing fresh khat leaves, there was a significant progressive rise in blood pressure and heart rate even one... 

In one study, 44 species of fungus were isolated from 30 samples of khat leaves gathered in Yemen. Researchers considered the toxins found in some of these species a threat to public health. 

Khat leaves have been illicitly bundled and shipped into the United States in increasing amounts since the... 

The fresh leaves of the khat shrub (Catha edulis) are chewed by several millions of people in East Africa and the Arabian peninsula for their euphoric and stimulating properties (284). The rather newly discovered alkaloid cathinone [(S)-a-aminopropiophenone] is responsible for the stimulating properties of khat (284). It has been shown that cathinone induces release at physiological catecholamine storage sites in a manner similar to that of amphetamine. Further results suggest that cathinone and amphetamine produce their stimulant effects via the same dopaminergic mechanism (599). The more recently discovered khat constituents merucathinone, merucathine, and pseudomerucathine were found to have only weak dopamine-releasing effects and were therefore considered unlikely to play an important role in the stimulatory actions of khat leaves (414). 

Khat, or qat, is a stimulant commonly used in East Africa, Yemen, and Southern Saudi Arabia. Khat leaves from the evergreen bush Catha edulis are typically chewed while fresh, but can also be smoked, brewed in tea, or sprinkled on food. Its use is culturally based. 

The major effects of khat on the central nervous system can be attributed to cathinone (S-(-)-alpha-aminopro-priophenone) in fresh khat leaves and cathine (norpseu-doephedrine) in dried khat leaves and stems. Cathinone, a phenylalkylamine, is the major active component and is structurally similar to amfetamine. It degrades to norp-seudoephedrine and norephedrine within days of leaf picking. Cathinone increases dopamine release and reduces dopamine re-uptake (1). 

Some khat leaves are grown with chemical pesticides. In 114 male khat users in two different mountainous areas of Yemen, users of khat that had been produced in fields in which chemical pesticides were used regularly had more acute gastrointestinal adverse effects (nausea and abdominal pain) and chronic body weakness and nasal problems (18). The authors suggested that organic chemical pesticides such as dimethoatecide can cause such adverse effects. 

Khat has amphetamine-like effects and can cause psychoses (132-138), including mania (139) and hypnagogic hallucinations (140). Two men developed relapsing short-lasting psychotic episodes after chewing khat leaves the psychotic symptoms disappeared without any treatment within 1 week (141). 

Kalix P. Amphetamine psychosis due to khat leaves. Lancet 1984 1(8367) 46. 

When 80 healthy volunteers chewed fresh khat leaves for 3 hours there were significant progressive rises in systolic and diastohc blood pressures and heart rate, without return to basehne 1 hour after chewing had ceased (3). 

Bilateral optic atrophy occurred in two patients who were long-standing users of khat leaves and had chewed larger quantities than usual (19). 

In 12 healthy volunteers who chewed Khat leaves or lettuce for 2 hours gastric emptying was significantly prolonged by khat (26). 

The Chinese drug ma huang (Ephedra sinica Stapf) has been used in China for more than SOOOyears. The alkaloid that is responsible for the CNS stimulant effects is ephedrine. The levorotatory erythro isomer ( l)is the most active of the four possible stereoisomers with that structural formula. Khat (kat, or qat) or Abyssinian tea Catha edulis Forskal) is the product from a small tree or shrub indigenous to tropical East Afiica. Khat leaves are chewed habitually by peoples in East Africa and certain other Arabian countries, and produce a mild CNS stimulant effect (2). The principal... 

Chapman MH, Kajihara M, Borges G, O Bierne J, Patch D, Dhillon AP, Crozier A, Morgan MY. Severe, acute liver injury and khat leaves. N Engl J Med 2010 362 1642-4. 

Basic drugs elicit a variety of physiological effects. Stimulants such as methamphetamine can act as haUudnogens at higher doses, while the opiate alkaloids are analgesic and promote general depression of the central nervous system. Many natural products, such as cocoa leaves, peyote, and khat leaves, have been used for hundreds of years. Some— for example, LSD and mescaline— are associated with religious explorations or celebrations. 

Drug overdose Hagigat, which contains 200 mg of cathinone (one of the components of khat leaves), approximately equivalent to 555 g of khat, are marketed in Israel in capsules as a natural stimulant. Reports to Israel s poison control center of exposure to hagigat have been analysed [61 ]. During the 10-month data collection period, there were 34 reports about patients aged 16-54 (median 25) years, 24 men and 10 women. In two cases the drug was inhaled. Myocardial ischemia was... 

Stimulants Amphetamines (speed) Cocaine (coke) Crack cocaine Khat Energy, euphoria, alermess Overactive, agitation Insomnia i Appetite T Confidence Timpulsivity Crash dysphoria, fatigue Can trigger psychosis. Khat - leaves, commonly chewed in Somali/Yemeni... 

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