Risk assessment of khat use in the Netherlands
In preparing a decision about the legal status of khat in the Netherlands, the Dutch Minister of Health requested CAM (Coordination point Assessment and Monitoring new drugs) to assess the overall risk of khat in the Netherlands. The present paper is a redraft of a report which formed the scientific basis of the risk evaluation procedure (October 2007). This report reviews the scientific data about khat available in the international literature. In addition, the report contains some information specific for the Netherlands (prevalence, availability of khat and public order aspects).
The main psychoactive compounds in khat leaves are cathine and cathinone, which are some 2- to 10-fold less active than amphetamine. Acute health problems are rarely seen, and are usually related with malnutrition, social and financial problems. Khat has a low addictive potential. Chronic toxicity of khat is modest when used in low amounts, whereas at high levels, khat use is associated with adverse effects, like hypertension, heart rhythm disorders, insomnia and loss of appetite. In addition, khat users show a higher prevalence of cancers in the digestive tract. At population level, khat does not lead to specific health risks in the Netherlands, as its use is confined to East-African immigrants.
A relationship between khat use and psychiatric disorders has been suggested, but the reports are contradictory, and such studies are presumably heavily confounded by posttraumatic and social stress. In the Netherlands (and other countries), khat use occasionally leads to minor disturbance of civil order in the public domain (loud talking, spitting), but is not related to criminal activities. Following the assessment, CAM estimated the overall risk potential of khat use in the Netherlands as very low. A similar conclusion may be drawn for countries with a comparable prevalence of khat use and khat related public order disturbance.
Discussion and overall conclusion
In summary, the adverse health effects of khat use may be regarded as very low. This view is based on its general toxicity profile, its low prevalence of use in the general population, its low consumption rate and the low criminal involvement in the Netherlands. In short, the nature of the acute effects of khat is not alarming and similar to those of amphetamine. Furthermore, chronic khat use is associated with an increased number of cardiovascular events like hypertension and myocard infarct, but serious khat related cardiovascular incidents have not been reported by e.g. emergency units of hospitals. Some periodontal diseases and gastro-intestinal complaints seem to be associated with khat use, but the effects observed are mild and the epidemiological evidence for an association very weak.
The abuse potential of khat is low and khat dependence is low. Mild craving and tolerance to khat effects exists but there is no definite withdrawal syndrome. There is no strong, and even contradictory, evidence for a causal relation between khat use and psychiatric morbidity. Most studies suffer from confounding, like the presence of post traumatic stress disorder (PTSD), chronic psychotic disorders, social stress and personal factors such as multi illicit drug use, medication and the relatively low socio-economic background of drug users. Moreover, psychotic reactions to khat are rare and psychiatric institutions do not report a frequent admission of patients with khat related psychiatric disorders. Obviously though, like other illicit psychostimulants, the use of khat is contraindicated in subjects with an increased psychiatric susceptibility. Moreover, in the Netherlands no criminal activities and no fatal accidents related to khat use have been observed and its prevalence is stable.
Quite alarming is the high prevalence of oral, head and neck cancers in khat users. Considering the low prevalence of khat use in the Netherlands, the impact of this adverse effect is estimated as low. On the other hand, this severe disease remains a critical effect of khat use. This further implies that the adverse risk of khat use may be significantly higher in those countries where khat is used much more frequently. Similarly, this may be the case in countries where khat is used under depraving socio-economic conditions such as poverty, social isolation, state of war, high criminality and persecution.
Regulatory Toxicology and Pharmacology 52 (2008) 199–207