Drug & supplement interaction

Quillaia + Pretomanid

Pretomanid brand name: Pretomanid.

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

Quillaia has a moderate interaction with Pretomanid. Theoretically, concomitant use of quillaia with immunosuppressant drugs might decrease the effectiveness of these drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Quillaia and Pretomanid

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

Moderate

IMMUNOSUPPRESSANTS

Why this applies to Pretomanid

Pretomanid falls under IMMUNOSUPPRESSANTS — the group Quillaia interacts with.

Theoretically, concomitant use of quillaia with immunosuppressant drugs might decrease the effectiveness of these drugs.
In vitro research shows that some quillaia constituents have immunostimulant effects.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the honest take on pairing quillaia with pretomanid: the interaction in our database is built around immunosuppressant drugs, and it rests on lab (test-tube) findings that some quillaia compounds may stir up the immune system. That's why it's flagged as theoretical only, with no real human evidence behind it.

Pretomanid isn't actually an immunosuppressant. It's an antibacterial that directly kills the TB bacteria, so the proposed immune-stimulating concern doesn't really map onto how this drug works. In practice I wouldn't expect quillaia to weaken your TB treatment. Still, MDR-TB therapy is too important to gamble with, and concentrated quillaia supplements can irritate the gut. Please run any herbal product past your pharmacist or TB doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. Wu JY, Gardner BH, Murphy CI, et al. Saponin adjuvant enhancement of antigen-specific immune responses to an experimental HIV-1 vaccine. J Immunol 1992;148:1519-25. DOI
  4. Fleck JD, Betti AH, da Silva FP, et al. Saponins from Quillaja saponaria and Quillaja brasiliensis: particular chemical characteristics and biological activities. Molecules 2019;24(1). pii: E171. 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

Quillaia Also Interacts With Other Medications

Quillaia has 120 moderate known drug interactions in our database — the Pretomanid one above is one of them. If you take anything else, check it against the full list below.

Moderate 120 No known interaction 2,710 (incl. Pretomanid)
Taking anything else?

Check Another of Your Medications Against Quillaia

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

Everything else you take

See Every Supplement That Interacts With Pretomanid

This page covers Quillaia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pretomanid page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 10 major · 122 moderate · 11 minor.

From our pharmacist’s overview on the Pretomanid page

“Pretomanid is reserved for highly drug-resistant tuberculosis, and it can stress the liver and lengthen the heart's QT interval, so the supplements on this page deserve genuine care. Ten of the 143 ingredients on file carry a major rating, and nearly all of those either compound the liver risk (alcohol in beer or wine is the plainest e…”

Reviewed by 2 · Jul 18, 2026

Open the Pretomanid interaction page

How much people look this up

Where Quillaia and Pretomanid 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 Quillaia
Top half

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

29 days ago today
Medication Pretomanid
Steady interest

#2,071 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 Quillaia

What is Quillaia?

  • Cough and chest congestion
  • Foaming agent in beverages
  • Vaccine adjuvant (in pharmaceutical manufacturing)
  • Washing and cleansing (traditional soap)
  • Skin conditions

Quillaia (soap bark tree) is a plant whose bark contains foaming compounds called saponins, and it is widely used as an emulsifier in foods and drinks. As a supplement or herbal remedy its benefits are not well proven, and large amounts can be irritating or toxic, so it should be used cautiously and only as directed.

Read the full Quillaia monograph & all interactions
Medication

About Pretomanid

What Is Pretomanid Used For?

Brand name: Pretomanid

Pretomanid Tablet is used only as part of a three-drug regimen — together with bedaquiline and linezolid — to treat adults with pulmonary (lung) tuberculosis that is resistant to multiple antibiotics, including isoniazid, rifamycins, a fluoroquinolone, and a second-line injectable TB drug. It is also used for adults whose TB is resistant to isoniazid and rifampin and who cannot tolerate or are not responding to standard TB therapy.

Pretomanid Tablets are not for drug-sensitive TB, latent (inactive) TB infection, TB outside the lungs, or TB that responds to standard treatment. They should only be used in combination with bedaquiline and linezolid — safety and effectiveness with other drug combinations have not been established.

See full Pretomanid drug information
Keep checking

Other Drugs & Quillaia

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

0Major
120Moderate
0Minor
2,709No known interaction
120 Moderate 2,709 No interaction
Moderate

120 interactions

Showing 60 of 120 moderate interactions — see all 120 on the Quillaia page.

No interaction 2,709 drugs checked — show the list

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

Showing the 60 most looked-up of 2,709 medications checked with no known interaction — see the full Quillaia list.

See the full Quillaia interactions page
See every supplement checked against Pretomanid, 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
Quillaia monograph › Uses, safety, and every drug interaction in one place Pretomanid supplement interactions › Every supplement checked against Pretomanid, ranked by severity Pretomanid drug information › The full plain-English guide to this medication 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 Quillaia and Pretomanid Together: Common Questions

Can you take Quillaia with Pretomanid?
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 Quillaia and Pretomanid 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 Pretomanid and Quillaia?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.