Khat (Catha edulis)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
Abyssinian tea, African salad, Arabian-tea, bushman's tea, cat, cathine, cathinone, Catha edulis, Celastraceae (family), Celastrus edulis, chat, chaat (Arabic), gat (Arabic), herbal ecstasy, kat (Arabic), kus es Salahin (Arabic), miraa, oat, phenylpropanolamine, qat (Yemen), qut, somali tea, tchaad (Arabic), tohai (Arabic), tohat (Arabic), tshcut (Arabic).
Khat is believed to have originated in Ethiopia. It is a flowering evergreen plant native to tropical East Africa. Khat has been grown for use as a stimulant for centuries and predates the use of coffee.
Khat is an agent that has been used in social settings to induce feelings of euphoria and pleasure. Medicinally, it has been used to treat depression and to enhance work capacity. Khat has also been used as an aphrodisiac, to treat premature ejaculation, and to enhance sexual desire.
Currently, there are no well-designed clinical trials evaluating khat for any indication. Two poorly documented trials evaluated khat in cognitive function. One study revealed no difference in cognitive function in the elderly with khat use. In the other study, cognitive functioning was negatively affected by khat use.
Fresh khat leaves contain cathinone - a Schedule I drug under the Controlled Substances Act; however, the leaves typically begin to deteriorate after 48 hours, causing the chemical composition of the plant to break down. Once this occurs, the leaves contain cathine, a Schedule IV drug. Khat is currently illegal in the United States.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Khat has been evaluated for its cognitive effects; however, the results are mixed with some studies showing benefit and others showing negative effects. Additional study is needed in this area to clarify these findings.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
Appetite suppressant, depression, gastric ulcers, fatigue, male infertility, obesity, physical work capacity, premature ejaculation, sexual activity enhancement, stimulant.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (over 18 years old)
There is no proven safe or effective dose for khat. However, approximately 100-200 grams of fresh leaves have been chewed, one at a time for their stimulant effects. The juice can be swallowed while the residue is retained in the cheek and later expelled. A juice has also been made by blending khat with water and lemon and then filtering the mixture. A tincture can be made by alcohol extraction of the active ingredients.
Children (under 18 years old)
There is no proven safe or effective dose for khat in children, and use in not recommended.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid in individuals with a known allergy or hypersensitivity to Cathus edulis or members of the Celastraceae family.
Side Effects and Warnings
Fresh khat leaves contain cathinone - a Schedule I drug under the Controlled Substances Act; however, the leaves typically begin to deteriorate after 48 hours, causing the chemical composition of the plant to break down. Once this occurs, the leaves contain cathine, a Schedule IV drug, which is similar in structure to amphetamine.
The stimulatory effect associated with khat has been documented with delusions, paranoia, hypomania, mood swings, depression, irritability, insomnia, and increased alertness. There have also been reports of persistent hypnagogic hallucinations caused by khat use.
Khat may cause nervousness, nightmares, aggressiveness, excitement, talkativeness, manic behavior, and hyperactivity. Khat chewing has dependency potential and may lead to dependence and addiction. Avoid using in patients with psychotic personalities. Use cautiously in patients with motor tics and Tourette's syndrome. Theoretically, khat may exacerbate motor tics and Tourette's syndrome. Khat is currently illegal in the United States.
Although not well studied in humans, khat may increase respiratory rates, increase systolic and diastolic blood pressure and heart rate, or cause acute myocardial infarction (heart attack). Other reported side effects include gastritis (stomach inflammation), malnutrition, hemorrhoidal disease, constipation, and oral carcinoma. Avoid holding khat in the cheek for extended periods of time to avoid oral infection.
Use cautiously in patients with hypertension (high blood pressure), tachycardia (fast heart rates), or cardiovascular disease because khat may increase blood pressure and heart rate. Khat should also be used cautiously in patients taking antihypertensives (blood pressuring lowering agents). Theoretically, khat may antagonize the effects of these drugs.
Fasciola hepatica infection, a parasite infection, has been reported after the chewing of khat leaves. Loss of appetite and anorexia has also been noted.
Methcathinone, a methyl derivative of cathinone, has been reported to cause mydriasis (dilation of the pupil).
Use cautiously in patients taking stimulant drugs or herbs. Increased stimulant effects may occur. Avoid driving after khat use; there are reports of impaired driving and psychophysical function. Avoid using in patients with glaucoma.
Pregnancy and Breastfeeding
Khat is not recommended for use in pregnant or breastfeeding women due to possible reductions in birth weight, birth defects and breastfeeding inhibition.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Use khat cautiously in patients taking amoxicillin or ampicillin. Khat may reduce the effectiveness of these drugs. These two antibiotics, particularly ampicillin, should be taken two hours after khat chewing.
Sympathomimetic effects of khat such as mydriasis (dilation of the pupil) and hypertension (high blood pressure) may be antagonized by antiadrenergic drugs including clonidine, reserpine, or terazosin.
Theoretically, khat may antagonize the effects of heart medications or blood pressure lowering agents. Khat has been reported to cause an increase in systolic and diastolic blood pressure and heart rate.
Use cautiously in patients taking beta-blockers or tricyclic antidepressants. Theoretically, khat may increase the risk of cardiovascular side effects with these drugs.
Khat may cause central nervous system (CNS) stimulation and use with other CNS stimulants may lead to additive effects. Stimulant and amphetamine-like effects are likely due to the phenylalkylamine alkaloid cathinone.
Theoretically, concurrent use of khat with monoamine oxidase inhibitors may cause hypertensive (high blood pressure) crisis.
Interactions with Herbs and Dietary Supplements
Khat may antagonize the effects of antihypertensive (blood pressure lowering) herbs and supplements. Khat has been reported to cause an increase in systolic and diastolic blood pressure and heart rate. Caution is advised.
Theoretically, concurrent use of khat with herbs with monoamine oxidase inhibitor-like activity may cause hypertensive (high blood pressure) crisis.
Theoretically, khat may increase the stimulant effects if taken with stimulant herbs and supplements, such as guarana or ephedra.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Adeoya-Osiguwa SA, Fraser LR. Cathine and norephedrine, both phenylpropanolamines, accelerate capacitation and then inhibit spontaneous acrosome loss. Hum.Reprod. 2005;20(1):198-207. View Abstract
Al Motarreb AL Broadley KJ. Coronary and aortic vasoconstriction by cathinone, the active constituent of khat. Auton.Autacoid.Pharmacol 2003;23(5-6):319-326. View Abstract
Al Motarreb A, Briancon S, Al Jaber N, et al. Khat chewing is a risk factor for acute myocardial infarction: a case-control study. Br J Clin Pharmacol 2005;59(5):574-581. View Abstract
Al Zubairi A, Al Habori M, Al Geiry A. Effect of Catha edulis (khat) chewing on plasma lipid peroxidation. J.Ethnopharmacol. 2003;87(1):3-9. View Abstract
Belhadj-Tahar H, Sadeg N. Methcathinone: a new postindustrial drug. Forensic Sci Int 10-4-2005;153(1):99-101. View Abstract
Dimba EA, Gjertsen BT, Bredholt T, et al. Khat (Catha edulis)-induced apoptosis is inhibited by antagonists of caspase-1 and -8 in human leukaemia cells. Br.J.Cancer 11-1-2004;91(9):1726-1734. View Abstract
Hassan NA, Gunaid AA, El Khally FM, et al. Khat chewing and arterial blood pressure. A randomized controlled clinical trial of alpha-1 and selective beta-1 adrenoceptor blockade. Saudi.Med J 2005;26(4):537-541. View Abstract
Hassan NA, Gunaid AA, El Khally FM, et al. The effect of chewing Khat leaves on human mood. Saudi.Med.J. 2002;23(7):850-853. View Abstract
Kassim S, Croucher R. Khat chewing amongst UK resident male Yemeni adults: an exploratory study. Int Dent.J 2006;56(2):97-101. View Abstract
Kuczkowski KM. Herbal ecstasy: cardiovascular complications of khat chewing in pregnancy. Acta Anaesthesiol.Belg. 2005;56(1):19-21. View Abstract
Murugan N, Burkhill G, Williams SG, et al. The effect of khat chewing on gallbladder motility in a group of volunteers. J.Ethnopharmacol. 2003;86(2-3):225-227. View Abstract
Nasher AA, Qirbi AA, Ghafoor MA, et al. Khat chewing and bladder neck dysfunction. A randomized controlled trial of alpha 1-adrenergic blockade. Br.J.Urol. 1995;75(5):597-598. View Abstract
Patel NB. Mechanism of action of cathinone: the active ingredient of khat (Catha edulis). East Afr.Med.J. 2000;77(6):329-332. View Abstract
Toennes SW, Kauert GF. Driving under the influence of khat--alkaloid concentrations and observations in forensic cases. Forensic Sci.Int. 2-10-2004;140(1):85-90. View Abstract
Toennes SW, Harder S, Schramm M, et al. Pharmacokinetics of cathinone, cathine and norephedrine after the chewing of khat leaves. Br.J.Clin.Pharmacol. 2003;56(1):125-130. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017