Drug & supplement interaction

Calabar Bean + Hydrocodone/Chlorpheniramine

Hydrocodone/Chlorpheniramine brand name: Tussionex.

Minor Interaction
The bottom line Minor

Calabar Bean has a minor interaction with Hydrocodone/Chlorpheniramine. Theoretically, taking calabar bean might reduce the effects of anticholinergic drugs.

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

Calabar Bean and Hydrocodone/Chlorpheniramine

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

Minor

ANTICHOLINERGIC DRUGS

Why this applies to Hydrocodone/Chlorpheniramine

Hydrocodone/Chlorpheniramine falls under ANTICHOLINERGIC DRUGS — the group Calabar Bean interacts with.

Theoretically, taking calabar bean might reduce the effects of anticholinergic drugs.
Physostigmine, a constituent of calabar bean, reverses the effects of belladonna and other drugs with anticholinergic activity.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the gist for Tussionex, which pairs hydrocodone (an opioid cough suppressant) with chlorpheniramine (an antihistamine that has drying, anticholinergic effects). Calabar bean contains physostigmine, which makes the body's acetylcholine build up. Since chlorpheniramine works partly by blocking acetylcholine, this supplement could, in theory, push back against that drying action, possibly easing some side effects like dry mouth or sedation. This goes the opposite direction of how most interactions work because the supplement counters, rather than boosts, the drug.

Honestly, this is a theoretical concern based on pharmacology, not real-world reports, and it's rated minor and unlikely. The bigger issue is that Calabar bean is genuinely poisonous and shouldn't be eaten at all. Please run any questions by your pharmacist or doctor.

References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 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

Calabar Bean Also Interacts With Other Medications

Calabar Bean has 194 minor known drug interactions in our database — the Hydrocodone/Chlorpheniramine 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 Calabar Bean

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

Everything else you take

See Every Supplement That Interacts With Hydrocodone/Chlorpheniramine

This page covers Calabar Bean only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrocodone/Chlorpheniramine page lists 258 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Grapefruit (major).

By severity: 12 major · 204 moderate · 42 minor.

From our pharmacist’s overview on the Hydrocodone/Chlorpheniramine page

“Tussionex (hydrocodone with chlorpheniramine) pairs an opioid with a sedating antihistamine, so anything that deepens drowsiness or slows breathing is a genuine hazard, and 78 of the 258 supplements on file do exactly that. Alcohol in any form tops that group, and kava carries a major rating for the same reason.”

Reviewed by 2 · Jul 18, 2026

Open the Hydrocodone/Chlorpheniramine interaction page

How much people look this up

Where Calabar Bean and Hydrocodone/Chlorpheniramine 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 Calabar Bean
Steady interest

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

29 days ago today
Medication Hydrocodone/Chlorpheniramine
Steady interest

#2,581 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 Calabar Bean

What is Calabar Bean?

Calabar Bean
  • Source of physostigmine (a prescription drug ingredient)
  • Historically used in 'trial by ordeal' rituals
  • Traditional pain relief and anti-inflammatory uses
  • Historically used for eye conditions (glaucoma)
  • Historically used as a poison

Calabar bean is a highly poisonous West African seed that contains physostigmine, a powerful cholinesterase inhibitor. It is not a safe dietary supplement, and eating the bean can cause serious poisoning or death. Only the purified, regulated drug physostigmine has a legitimate medical use, and that must be prescribed and monitored by a doctor.

Read the full Calabar Bean monograph & all interactions
Keep checking

Other Drugs & Calabar Bean

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

0Major
0Moderate
194Minor
2,635No known interaction
Minor

194 interactions

Showing 60 of 194 minor interactions — see all 194 on the Calabar Bean page.

No interaction 2,635 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 Calabar Bean and Hydrocodone/Chlorpheniramine Together: Common Questions

Can you take Calabar Bean with Hydrocodone/Chlorpheniramine?
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 Calabar Bean and Hydrocodone/Chlorpheniramine 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

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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.