Drug & supplement interaction

Calabar Bean + Hydroxyzine

Hydroxyzine brand names: Atarax, Vistaril, Ucerax.

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

Calabar Bean has a minor interaction with Hydroxyzine. 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 Hydroxyzine

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

Minor

ANTICHOLINERGIC DRUGS

Why this applies to Hydroxyzine

Hydroxyzine 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 basic idea. Hydroxyzine is an antihistamine that also has mild anticholinergic activity, meaning it quiets certain nerve signals (that's part of why it makes you sleepy or dry-mouthed). Calabar bean contains physostigmine, which does the opposite: it boosts that same nerve messenger, acetylcholine. So in theory, the two pull in different directions, and the bean could blunt some of hydroxyzine's calming or sedating effect.

That said, this is purely a theoretical concern drawn from how the chemicals behave, not from real cases, and it's rated minor and unlikely. The far bigger issue is that Calabar bean itself is genuinely poisonous and is not a safe thing to take at all. Please don't use it, and check with your pharmacist or doctor about anything you're considering alongside hydroxyzine.

Contact Dr. Brian directly if you have additional questions on this interaction
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 Hydroxyzine one above is one of them. If you take anything else, check it against the full list below.

Minor 194 No known interaction 2,636 (incl. Hydroxyzine)
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.

From our Q&A

Questions About Calabar Bean or Hydroxyzine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Calabar Bean or Hydroxyzine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Hydroxyzine

This page covers Calabar Bean only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydroxyzine page lists 183 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Henbane (major), Scopolia (major) and St. John's Wort (major).

By severity: 5 major · 135 moderate · 43 minor.

From our pharmacist’s overview on the Hydroxyzine page

“Hydroxyzine (Atarax, Vistaril) is a sedating antihistamine for itching and anxiety, so read this list closely before pairing it with any supplement. Five of the 183 ingredients on file rate major, and those come first: grapefruit and St.”

Reviewed by 2 · Jul 18, 2026

Open the Hydroxyzine interaction page

How much people look this up

Where Calabar Bean and Hydroxyzine 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

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

29 days ago today
Medication Hydroxyzine
Top 25%

#438 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
Medication

About Hydroxyzine

What Is Hydroxyzine Used For?

Brand names: Atarax, Vistaril, Ucerax

Hydroxyzine is used to relieve anxiety and tension related to psychoneurosis (anxiety-based mental health conditions) and as a supportive treatment when anxiety is part of another medical condition. Oral forms — including tablets, capsules, and oral solution — are used for anxiety relief and to manage itching (pruritus) caused by allergic conditions such as chronic urticaria (hives), atopic dermatitis, contact dermatitis, and histamine-driven itch. Oral forms are also used as a sedative before and after surgery or general anesthesia.

Hydroxyzine Hydrochloride intramuscular injection is used specifically when a shot is needed — for example, in acute psychiatric or emotional emergencies, acute alcohol withdrawal with anxiety symptoms or delirium tremens, control of nausea and vomiting (except during pregnancy), and as pre- and post-operative or pre- and post-partum supportive medication to reduce narcotic requirements and control nausea.

See full Hydroxyzine drug information
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
194 Minor 2,635 No 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

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

Showing the 60 most looked-up of 2,635 medications checked with no known interaction — see the full Calabar Bean list.

See the full Calabar Bean interactions page
See every supplement checked against Hydroxyzine, 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
Calabar Bean monograph › Uses, safety, and every drug interaction in one place Hydroxyzine supplement interactions › Every supplement checked against Hydroxyzine, ranked by severity Hydroxyzine 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 Calabar Bean and Hydroxyzine Together: Common Questions

Can you take Calabar Bean with Hydroxyzine?
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 Hydroxyzine 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 Hydroxyzine and Calabar Bean?

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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.