ABSTRACT
Objectives: This study aimed to evaluate the effect of khat [Catha edulis] on chloroquine [CQ] bioavailability in healthy Yemeni adults and its effect on CQ plasma levels and parasite clearance among malaria patients
Methods: This study took place between January and April 2007 in Bajil and Sana'a, Yemen. Two CQ doses [600 mg each] were given to 15 healthy males on separate occasions; the first dose was followed by a khat-chewing session [phase one] while controls abstained from khat-chewing for the second [phase two]. Additionally, 103 patients with Plasmodium falciparum-induced malaria, including both regular khat chewers [n = 57] and non-khat chewers [n = 46], were treated with CQ [25 mg/kg] over three days. Pharmacokinetic parameters were analysed among both controls and malaria patients. Parasite clearance was also investigated for the latter group
Results: The mean area under the concentration-time curve [AUC] was 2,108.9 versus 2,797.4 ng/hour/mL, mean peak plasma concentration [Cmax] was 415.6 versus 508.7 ng/mL and mean time to reach Cmax was 3.8 versus 3.6 hours for controls in phase one versus phase two, respectively; both AUC and Cmax levels were significantly reduced by khat-chewing [P <0.050]. For khat- versus non-khat-chewing malaria patients, mean plasma CQ concentrations were 266.4 ng/mL versus 427.5 ng/mL [P <0.001]. Furthermore, CQ was effective in 71.7% and 75.4% of non-khat- and khat-chewing malaria patients, respectively [P = 0.823]
Conclusion: Khat-chewing was found to significantly reduce plasma CQ levels among healthy volunteers and malaria patients. While receiving CQ treatment, patients should be advised not to chew khat