Drug & supplement interaction

Calumba + Bismuth Subcarbonate, Calcium Carbonate, Opium

Bismuth Subcarbonate, Calcium Carbonate, Opium brand name: Diabismul.

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

Calumba has a minor interaction with Bismuth Subcarbonate, Calcium Carbonate, Opium. Theoretically, calumba might decrease the effectiveness of antacids.

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

Calumba and Bismuth Subcarbonate, Calcium Carbonate, Opium

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

Minor

ANTACIDS

Why this applies to Bismuth Subcarbonate, Calcium Carbonate, Opium

Bismuth Subcarbonate, Calcium Carbonate, Opium falls under ANTACIDS — the group Calumba interacts with.

Theoretically, calumba might decrease the effectiveness of antacids.
There are reports that calumba increases stomach acid.
Severity Minor 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 simple version. The medicine you asked about (Diabismul) contains an antacid component (calcium carbonate) along with bismuth and a small amount of opium to help with diarrhea and upset stomach. Calumba is a traditional bitter tonic, and bitters are thought to gently ramp up stomach acid and digestive juices. So in theory, taking calumba could push back a little against the acid-neutralizing job of the calcium carbonate, making that part of your medicine feel less effective for heartburn or sour stomach.

That said, this is very weak, mostly anecdotal evidence, and it's rated minor. It isn't expected to be dangerous. If you use Diabismul regularly and want to try calumba, just run it by your pharmacist or doctor first so nothing gets in the way of your relief.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Calumba Also Interacts With Other Medications

Calumba has 35 minor known drug interactions in our database — the Bismuth Subcarbonate, Calcium Carbonate, Opium one above is one of them. If you take anything else, check it against the full list below.

Minor 35 No known interaction 2,795 (incl. Bismuth Subcarbonate, Calcium Carbonate, Opium)
Taking anything else?

Check Another of Your Medications Against Calumba

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

Everything else you take

See Every Supplement That Interacts With Bismuth Subcarbonate, Calcium Carbonate, Opium

This page covers Calumba only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Bismuth Subcarbonate, Calcium Carbonate, Opium page lists 30 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Cinchona (moderate), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).

By severity: 1 major · 10 moderate · 19 minor.

From our pharmacist’s overview on the Bismuth Subcarbonate, Calcium Carbonate, Opium page

“Diabismul (bismuth subcarbonate, calcium carbonate, and opium) is an older antidiarrheal, and its supplement interactions deserve real attention, starting with activated charcoal, the single major-rated entry on this page. Charcoal binds a wide swath of medicines in the gut and can sharply cut how much your body absorbs.”

Reviewed by 2 · Jul 18, 2026

Open the Bismuth Subcarbonate, Calcium Carbonate, Opium interaction page

How much people look this up

Where Calumba and Bismuth Subcarbonate, Calcium Carbonate, Opium 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 Calumba
Top half

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

29 days ago today
Medication Bismuth Subcarbonate, Calcium Carbonate, Opium
Top 10%

#202 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 Calumba

What is Calumba?

  • Poor appetite
  • Digestive upset and indigestion
  • Nausea
  • Diarrhea
  • As a bitter tonic

Calumba is the dried root of an African climbing plant that has long been used as a bitter tonic to stimulate appetite and ease digestive complaints. Modern scientific evidence for these uses is very limited, and its safety has not been well studied, so it should be used cautiously and avoided during pregnancy and breastfeeding.

Read the full Calumba monograph & all interactions
Keep checking

Other Drugs & Calumba

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

0Major
0Moderate
35Minor
2,794No known interaction
35 Minor 2,794 No interaction
Minor

35 interactions

No interaction 2,794 drugs checked — show the list

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

Showing the 60 most looked-up of 2,794 medications checked with no known interaction — see the full Calumba list.

See the full Calumba interactions page
See every supplement checked against Bismuth Subcarbonate, Calcium Carbonate, Opium, 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
Calumba monograph › Uses, safety, and every drug interaction in one place Bismuth Subcarbonate, Calcium Carbonate, Opium supplement interactions › Every supplement checked against Bismuth Subcarbonate, Calcium Carbonate, Opium, 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 Calumba and Bismuth Subcarbonate, Calcium Carbonate, Opium Together: Common Questions

Can you take Calumba with Bismuth Subcarbonate, Calcium Carbonate, Opium?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Calumba and Bismuth Subcarbonate, Calcium Carbonate, Opium interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Bismuth Subcarbonate, Calcium Carbonate, Opium and Calumba?

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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.