Drug & supplement interaction

Khat + Chloroquine, Primaquine Phosphate

Chloroquine, Primaquine Phosphate brand name: Aralen / Primaquine.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Khat has a moderate interaction with Chloroquine, Primaquine Phosphate. Chewing khat after taking chloroquine appears to decrease the absorption of chloroquine.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceA
What do Severity, Likelihood & Evidence mean?
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Interaction report

Khat and Chloroquine, Primaquine Phosphate

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CHLOROQUINE (Aralen)

Chewing khat after taking chloroquine appears to decrease the absorption of chloroquine. Chewing khat reduces the chloroquine area under the curve (AUC) by 25% and the peak plasma concentration by 18.3%. However, in patients with malaria, chewing khat did not significantly reduce the rate of treatment success with chloroquine compared to patients that did not chew khat. Chewing khat while taking chloroquine reduces the absorption of chloroquine and might reduce the efficacy of chloroquine. Until more is known, people taking chloroquine for the treatment or prevention of malaria should avoid chewing khat.
Severity Moderate Likelihood Probable Evidence A

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the practical takeaway: studies show that chewing khat while taking chloroquine lowers how much of the drug your body actually absorbs. In a good-quality trial, khat dropped chloroquine blood levels by roughly 20 to 25 percent. Chloroquine is not a prodrug, so less absorption simply means less active medicine working against malaria parasites.

The reassuring part is that in people actually treated for malaria, khat did not clearly lower cure rates. Still, with something as serious as malaria, you don't want to gamble on weaker protection. Add to that khat's own heart and blood pressure risks (and the fact that it's illegal in the U.S.), and the safe move is to avoid it. Please talk with your doctor or pharmacist before changing anything.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Issa FH, Al-Habori M, Chance ML. Effect of Khat (Catha edulis) Use on the Bioavailability, Plasma Levels and Antimalarial Activity of Chloroquine. Sultan Qaboos Univ Med J. 2016;16(2):e182-8. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Khat Also Interacts With Other Medications

Khat has 4 major, 400 moderate known drug interactions in our database — the Chloroquine, Primaquine Phosphate one above is one of them. If you take anything else, check it against the full list below.

Major 4 Moderate 400 No known interaction 2,426 (incl. Chloroquine, Primaquine Phosphate)
Taking anything else?

Check Another of Your Medications Against Khat

Covers the 2,830 medications we’ve checked against Khat. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Chloroquine, Primaquine Phosphate

This page covers Khat only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chloroquine, Primaquine Phosphate page lists 30 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Hibiscus Sabdariffa (major), Biofeedback (moderate), Coffee Charcoal (moderate) and Dendrobium (moderate).

By severity: 2 major · 19 moderate · 9 minor.

Open the Chloroquine, Primaquine Phosphate interaction page

How much people look this up

Where Khat and Chloroquine, Primaquine Phosphate Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Khat
Top half

#403 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Chloroquine, Primaquine Phosphate
Steady interest

#1,663 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Khat

What is Khat?

Khat
  • Stimulant for energy and alertness
  • Euphoria and mood elevation
  • Reducing fatigue
  • Appetite suppression
  • Social and traditional ceremonies

Khat is a plant chewed for its amphetamine-like stimulant effects, but it carries serious risks including high blood pressure, heart problems, mental health effects, and dependence. It is a controlled substance and illegal in the United States and many other countries, so it should not be used.

Read the full Khat monograph & all interactions
Keep checking

Other Drugs & Khat

Browse every other medication we’ve checked against Khat — both the ones with a known interaction and the ones without. Select any drug for the full detail.

4Major
400Moderate
0Minor
2,425No known interaction
4 Major 400 Moderate 2,425 No interaction
Major

4 interactions

Moderate

400 interactions

Showing 60 of 400 moderate interactions — see all 400 on the Khat page.

No interaction 2,425 drugs checked — show the list

We also checked Khat against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,425 medications checked with no known interaction — see the full Khat list.

See the full Khat interactions page
See every supplement checked against Chloroquine, Primaquine Phosphate, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Khat monograph › Uses, safety, and every drug interaction in one place Chloroquine, Primaquine Phosphate supplement interactions › Every supplement checked against Chloroquine, Primaquine Phosphate, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Khat and Chloroquine, Primaquine Phosphate Together: Common Questions

Can you take Khat with Chloroquine, Primaquine Phosphate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Khat and Chloroquine, Primaquine Phosphate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Chloroquine, Primaquine Phosphate and Khat?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.