Khat

Scientific Name(S): Catha edulis Forsk. Family: Celastraceae

Common Name(S): Khat, qut, kat, chaat, Kus es Salahin, Tchaad, Tschut, Tohat, Tohai, Gat

Botany: A tall plant (9 to 12 feet) with a natural distribution limited to East Africa and the Arabian Peninsula (Kenya, the Yemens and Ethiopia). It grows best at high elevations, and its tender twigs and leaves are harvested almost year-round. Freshly harvested khat is wrapped in leaves and exported by air to neighboring African countries.

History: One of the most common forms of drug abuse in many East African nations involves chewing parts of the khat plant. Khat use has increased steadily over the last 50 years and has become a problem of significant social and medical importance. Because of its social acceptability and euphoriant effects, khat chewing often plays a dominant role in celebrations, meetings, marriages and other gatherings. Khat use is even prevalent in the Somali military. It is frequently issued to soldiers in their daily rations with the intention of inhibiting their need for food and sleep, as well as increasing their aggression. The amount of khat chewed is variable but is usually about 2 ounces. The tender leaves and stems, which lose their potency one day after harvest, are chewed and the juice is swallowed. It has a sweetish taste and astringent action. Large amounts of liquids are consumed while chewing because of the dryness induced by the plant.

Khat leaves have been used in traditional medicine for the treatment of depression, fatigue, obesity and gastric ulcers.

Uses of Khat

Khat leaves are chewed for stimulant and euphoriant effects, and used to treat obesity and gastric ulcers. Some users experience dysphoria and sedation.

Side Effects of Khat

Khat may cause oral cancer, cerebral hemorrhage, myocardial infarction, hypertension, testicular degeneration, low birth weight and a variety of other severe effects, including psychological addiction and the attendant ills.

Toxicology: Severe adverse effects have been associated with khat use; migraine, cerebral hemorrhage, myocardial infarction and pulmonary edema have been described, particularly in older and predisposed individuals. Hepatic cirrhosis of unknown etiology has been noted in khat users; poor diets and the potentially hepatotoxic effects of khat tannins may be contributing factors. Anaphrodesia is reported frequently by men during khat use. Although libido initially may be increased, a loss of sexual drive, spermatorrhea and subsequent impotence soon follow. In females, however, the situation is very different. Seventy-two percent of female users in one survey reported increased sexual desire, followed by an improvement in sexual performance in 78% of the respondents.

In vitro studies have demonstrated that a chloroform extract of khat leaves is cytotoxic in cultures of KB, 1 BR.3, and XP2B1 mammalian cells. This cytotoxicity appears to be due to inhibition of de novo RNA synthesis affecting all the cell strains tested; KB cells possessed some resistance to the toxicity. Oral cancers in certain regions of Saudia Arabia have been found to occur mostly among patients who had been chronic khat chewers.

Data from Allium cepa root tips suggest that (-)-cathinone is responsible for teratogenic and mutagenic effects of khat, since it caused clumping and condensation of chromosomes, sticky meta phases and anaphasic bridges. Animal studies indicate that cathinone can depress testosterone levels, degenerate testicular tissue and decrease sperm count and motility.

Several studies of full-term human newborns has shown that khat use by the mother is associated with significantly lower birth weight, but no differences in the rates of stillborns or congenital malformations were observed. A study of guinea pigs suggests that (+)-norpseudoephedrine in khat may reduce placental blood flow, impairing fetal growth.

A report of two cases has described bilateral optic atrophy in two khat users who consumed amounts larger than usual. This may have been an idiosyncratic reaction to khat.

Social Notes: In his excellent review of the use of khat in Somalia, Elmi warns that "the pleasant stimulation obtained when chewing khat induces many to abuse the drug. This may have damaging effects from a social and economic point of view. Some people may arrive at spending a great part of their earnings on khat, thus failing to ensure for themselves and their families important and vital needs. Excess of khat chewing may lead to family disintegration. The chewer shows (very often) irritability and spends much of the time away from home. These facts and the failure of sexual intercourse after chewing may endanger family life. For some countries where khat imports account for the loss of a sizable portion of the national income, there may be a serious economic balance of payments problem."

Summary: Khat is a plant product produced and consumed in East Africa and the Arabian Peninsula. Chewed for its euphoric effects, khat does not induce physical dependence. It does, however, induce psychological dependence and can cause serious physical and psychological side effects. Khat is now being exported worldwide and can represent a serious economic problem, with considerable social costs, for users.