Web Box 12.3 Use and Misuse of Khat

As mentioned in the main text, the chewing of khat leaves is a cultural tradition that dates back many hundreds of years in countries of the Horn of Africa and Arabian Peninsula (reviewed by Engidawork, 2017; Patel, 2019). Much like the previously described coca leaf chewing, the cultivation of Catha edulis and chewing of the khat leaves continues to the present day in these countries (Figure 1). Furthermore, immigration of people from those areas to other parts of the world, including Europe, Southeast Asia (particularly Indonesia), Australia, and North America, has contributed to an increase in global khat use. Authorities have estimated that 10 to 20 million people worldwide consume khat (Patel, 2019).

Like the other substances discussed in this chapter, khat is consumed for its stimulant properties. Users report feelings of euphoria, arousal, and increased energy. Other effects include sympathetic nervous system activation, insomnia, and suppression of hunger. Users may experience mild withdrawal symptoms of depressed mood and irritability when coming down from a khat “high.” Khat potency declines over several days once the leaves have been harvested. Thus, users need to obtain fresh leaves in order to experience the desired effects. A single chewing session may entail the consumption of 100 to 500 g of khat leaves over a period of 3 to 4 hours (Patel, 2019). Recent surveys conducted in Ethiopia have found a substantial number of khat users among high school and college students (Gebrie et al., 2018; Alemu et al., 2020; Mekuriaw et al., 2020). Users were most likely to be male, to have family and/or friends who are also khat chewers, and to additionally use alcohol and/or tobacco. Many also suffer from a mental disorder such as depression or anxiety, thus leading to the possibility (especially in the case of depressive symptomatology) of khat use for self-medication.

The major active ingredients of khat are cathinone and, to a lesser extent, the closely related substance cathine. Animal studies have shown that like amphetamine and methamphetamine, cathinone is both a DA reuptake inhibitor and DA releaser. Because of the similarity of cathinone’s mechanisms of action to those of amphetamine and methamphetamine, concerns have been raised about the possibility of khat users developing an addictive pattern of use. Animal studies have revealed rewarding and reinforcing properties of pure cathinone. Moreover, evidence for dependence in many khat users has been obtained by means of various psychological instruments adapted for this purpose (Odenwald and al’Absi, 2017; Patel, 2019). For these reasons, cathinone has been registered as a Schedule I substance, and possession and distribution of khat have been banned in many countries. As in the case of coca leaf chewing, this route of administration generally has lower addiction potential than other common routes of drug consumption. However, this does not preclude the possibility of khat dependence occurring with regular heavy use.

Lastly, some studies suggest that regular khat use may increase the risk of developing several kinds of health problems, including hypertension and other cardiovascular disorders (El-Menyar et al., 2015; Mega and Dabe, 2017; Geta et al., 2019), gastrointestinal disorders (Nigussie et al., 2013), periodontal disease (Kalakonda et al., 2017), and, at very high doses, psychotic reactions (Engidawork, 2017). We note, however, that except for the expected adverse effects of cathinone on the cardiovascular system, most of the other reported health effects need to be verified with more rigorous studies.

In summary, khat chewing has become a global issue that transcends the traditional, more restricted use of this plant in the countries of its origin. Because of its potential for misuse and even dependence, the growing use of khat by young students is of concern. Several adverse health effects have also been documented. Thus, cathinone, in the form of khat, needs to be included in the list of psychostimulants that have addictive potential when used regularly.

References

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El-Menyar, A., Mekkodathil, A., Al-Thani, H., and Al-Motarreb, A. (2015). Khat use: History and heart failure. Oman Med. J., 30, 77–82.

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