Khat

The use of khat (Catha edulis) while on medication may alter treatment outcome. In particular, the influence of khat on the metabolic activities of drug-metabolizing enzymes is not known. We performed a comparative 1-way crossover study to evaluate the effect of khat on cyto-chrome P450 (CYP)2D6 and CYP3A4 enzyme activity. After 1 week of khat abstinence, baseline CYP2D6 and CYP3A4 metabolic activities were determined in 40 Ethiopian male volunteers using 30 mg dextromethor-phan (DM) as a probe drug and then repeated after 1 week of daily use of 400 g fresh khat leaves. Urinary concentrations of cathinone and cathine were determined to monitor the subjects' compliance to the study protocol. Genotyping for CYP2D6*3 and CYP2D6*4 was done. Plasma DM, dextrorphan and 3-methoxymorphinan concentrations were quantified. CYP2D6 and CYP3A4 enzyme activities were assessed by comparing plasma log DM/dextrorphan and log DM/methoxymorphinan metabolic ratio (MR) respectively in the presence and absence of khat. Cytochrome 2D6 MR was significantly increased from baseline by concurrent khat use (paired t test, P = 0.003; geometric mean ratio, 1.38; 95% confidence interval [95% CI], 1.12–1.53). Moreover, the inhibition of CYP2D6 activity by khat was more pronounced in CYP2D6*1/*1 compared with CYP2D6*1/*4 genotypes (P = 0.01). A marginal inhibition of CYP3A4 activity in the presence of khat was observed (P = 0.24). The mean percentage increase of CYP2D6 and CYP3A4 MR from baseline by khat use was 46% (95% CI,20–72) and 31% (95% CI, 8–54), respectively. This is the first report linking khat use with significant inhibition of CYP2D6 metabolic activity in humans.

Abstract
Background: The estimate of the number of people chewing Khat globally ranges from 5 to 10 million people. Its use may result in a variety of effects due to the different compounds in it with effects on the gastro‐intestinal system and nervous system being the principal ones. Aim: To assess the prevalence, factors, and effects of Khat chewing among students of a college in Gondar town, northwestern Ethiopia. Subjects and Methods: An institution‐based cross‐sectional study was conducted from 15th to 20th of April 2009 on a total sample of 424 students who were selected using stratified random sampling technique. Data were collected by three of the principal investigators using a structured pretested data collection instrument and analyzed by Epi Info version 3.5.2. Results: The lifetime and current prevalence of Khat chewing among the respondents were 42% (168/400) and 32.5% (130/400), respectively. Sex (P < 0.01), religion (P < 0.001), and income (P < 0.01) showed statistically significant variation in Khat chewing. The commonest frequency of Khat chewing was once a day 33.1% (43/130) while alcohol (40.8% [53/130]) and cigarette (40.0% [52/130]) were the mostly used substances with Khat. More than half of the chewers (53.85% [70/130]) reported spending 1–4 h for one Khat chewing ceremony. Financially majority of the chewers reported spending up to 10 Ethiopian Birr (ETB) (1.13 United States Dollar) on Khat ( 54.6% [71/130]) and other substances (64.6% [84/130]). Nearly two‐thirds (62.3% [81/130]) of the chewers mentioned seeking concentration during study as their main reason for chewing. Among chewers, 83.1% (108/130) reported they faced problem associated to sleep disturbance, 82.3% (107/130) loss of appetite, and 80.8% (105/130) constipation. Conclusion: The prevalence of Khat chewing was fairly high among the students and the majority among them used other substances together with Khat. Spending of a significant amount of money and facing health problems were reported to be consequences of the habit. The college should take steps to make students aware of the ills of Khat chewing and associated habits.

Background: Education plays an important role and is a second major (non-medical dimensional) factor influencing the health status. Individuals demonstrate oral practices that impact the oral health positively or negatively. This study analyzes how self-reported oral practices are influenced by different educational levels among young adults in Jizan. Materials and Methods: The survey was conducted in four areas around University of Jizan. The survey subjects, aged between 15 and 34 years, completed the self-administered, structured questionnaire. Inter-group comparison was done using Chi-square test. Level of significance was fixed at P < 0.05. Results: Exactly 1597 subjects completed the survey. Of these, 644 (40.3%) had attained higher education, 884 (55.4%) had lower education, and 69 (4.3%) were illiterate. Statistical comparisons showed significant differences among the three groups with respect to the use of toothbrushes (χ2 = 88.67, P < 0.001), use of interdental cleaning aids (χ2 = 15.04, P < 0.001), siwak use (χ2 = 16.31, P < 0.001), cigarette smoking (χ2 = 14.28, P < 0.001), and khat chewing (χ2 = 38.1, P < 0.001). Siwak use was more among those with low educational level and illiterates. Further, smoking and khat chewing were significantly more prevalent among illiterates. Conclusion: The subjects with low education and the illiterates exercise harmful oral practices. This study indicates that educational level is responsible for inequities in oral practices.

Context: Consumption of khat leaves has been disseminated worldwide with the migration of its users from Arabia and Africa. Despite numerous reports regarding the associations of khat chewing with serious health impacts, a significant number of people worldwide uses khat daily, especially in its origin countries. The risk of co-administration of khat and drugs (prescription and over the-counter medications) is high among these individuals, leading to increase probability of adverse khat-drug interactions. The likelihood of khat-drug interactions could be higher than drug-drug interactions because drugs usually contain single chemical entities while almost all herbs (including khat) contain mixtures of pharmacologically active constituents. Aims: To review the literatures on how khat interacts with some drugs and whether it is favorable or not. Methods: The study was conducted as a systematic review. The electronic literature searches were made in Google search engine to access publications from databases like PubMed, Google Scholar, and Cochrane using the keywords 'khat', 'Catha edulis' in combination with the terms 'drug interaction', 'adverse-effects', 'side effects', 'adverse drug reaction', 'safety', and 'toxicity' to identify relevant articles. Results: A total of 250 articles was identified, and these articles were checked in terms of title, abstract, and content according to inclusion and exclusion criteria. Finally, 18 articles were included in the study. The khat use significantly interact with most drugs and may cause unpredictable pharmacological sequences. Conclusions: Healthcare providers suggest patients` khat abstinence during medication process. Future studies need to investigate the khat-clinical drugs interactions especially with chronic used drugs.