Drug & supplement interaction

Cinchona + Indapamide

Indapamide brand names: Lozol, Lozide.

Moderate Interaction
The bottom line Moderate

Cinchona has a moderate interaction with Indapamide. Theoretically, taking cinchona with other QT interval-prolonging drugs might cause an additive effect and increase the risk of ventricular arrhythmias.

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

Cinchona and Indapamide

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

Moderate

QT INTERVAL-PROLONGING DRUGS

Why this applies to Indapamide

Indapamide falls under QT INTERVAL-PROLONGING DRUGS — the group Cinchona interacts with.

Theoretically, taking cinchona with other QT interval-prolonging drugs might cause an additive effect and increase the risk of ventricular arrhythmias.
Quinidine and quinine, which are constituents of cinchona, prolong the QT interval.
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 concern with pairing cinchona and indapamide. Cinchona bark naturally contains quinine and quinidine, and both of those can stretch out something called the QT interval, which is a measure of your heart's electrical timing. Indapamide can do the same thing on its own, so stacking them together may add up and raise the small risk of an irregular, dangerous heartbeat.

There's an extra wrinkle: indapamide is a water pill that can lower potassium and magnesium, and low levels of those minerals make QT problems more likely. I'll be honest, this warning is theoretical and based on how these compounds behave, not solid case reports. Still, please check with your pharmacist or doctor before combining them, and don't change your indapamide on your own.

References
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.

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

Cinchona Also Interacts With Other Medications

Cinchona has 3 major, 472 moderate, 16 minor known drug interactions in our database — the Indapamide one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Cinchona

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

Everything else you take

See Every Supplement That Interacts With Indapamide

This page covers Cinchona only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Indapamide page lists 215 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 13 major · 179 moderate · 23 minor.

From our pharmacist’s overview on the Indapamide page

“A water pill like indapamide (Lozol) lowers blood pressure and pulls potassium down, and most of the 215 supplements and herbs on file press on those same levers. Thirteen entries rate major, so this is a list to read with real care rather than skim.”

Reviewed by 2 · Jul 18, 2026

Open the Indapamide interaction page

One more smart check

Taking Cinchona as Part of a Dietary Supplement Product? Check It for Interactions

We hold 12 real supplement products containing Cinchona, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cinchona. Your product may carry other ingredients that interact with Indapamide too, on top of Cinchona — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cinchona and Indapamide 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 Cinchona
Top half

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

29 days ago today
Medication Indapamide
Top half

#1,117 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 Cinchona

What is Cinchona?

Cinchona
  • Malaria (historical/traditional)
  • Fever
  • Leg cramps and restless legs
  • Digestive upset and loss of appetite
  • Bitter tonic

Cinchona bark is the natural source of quinine and has been used for centuries to treat malaria and fever, but the bark itself is not standardized and can be unpredictable and risky. Modern medicine uses purified, dose-controlled quinine instead, and the supplement form carries real dangers, including serious heart and blood problems. Talk to a pharmacist or doctor before using it, and avoid it during pregnancy.

Read the full Cinchona monograph & all interactions
Medication

About Indapamide

What Is Indapamide Used For?

Brand names: Lozol, Lozide

Indapamide tablets are used to treat high blood pressure (hypertension), either on their own or together with other blood pressure medications. Lowering blood pressure helps reduce the risk of related complications.

Indapamide tablets are also used to treat salt and fluid retention (edema) associated with congestive heart failure. In certain cases, indapamide may also be appropriate during pregnancy when swelling is caused by a medical condition rather than normal pregnancy changes — but routine use in otherwise healthy pregnant women is not recommended.

See full Indapamide drug information
Keep checking

Other Drugs & Cinchona

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

3Major
472Moderate
16Minor
2,338No known interaction
Major

3 interactions

Moderate

472 interactions

Showing 60 of 472 moderate interactions — see all 472 on the Cinchona page.

Minor

16 interactions

No interaction 2,338 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Cinchona and Indapamide Together: Common Questions

Can you take Cinchona with Indapamide?
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 Cinchona and Indapamide 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 Indapamide and Cinchona?

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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.