Drug & supplement interaction

Scopolia + Promazine

Promazine brand name: Sparine.

Major Interaction
The bottom line Major

Scopolia has a major interaction with Promazine. The alkaloid constituents of scopolia, including hyoscyamine, scopolamine, and atropine, could potentiate the effects and adverse effects of anticholinergic drugs.

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

Scopolia and Promazine

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

Major

ANTICHOLINERGIC DRUGS

Why this applies to Promazine

Promazine falls under ANTICHOLINERGIC DRUGS — the group Scopolia interacts with.

The alkaloid constituents of scopolia, including hyoscyamine, scopolamine, and atropine, could potentiate the effects and adverse effects of anticholinergic drugs.
Severity Major Likelihood Probable Evidence D

Interaction 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..

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

Here is the key thing to know: Promazine (Sparine) is an older phenothiazine that already carries its own anticholinergic punch. It can leave you with a dry mouth, blurry vision, constipation, trouble emptying your bladder, and sometimes a racing heart or confusion. Scopolia is loaded with strong anticholinergic alkaloids like atropine and scopolamine, so pairing the two basically stacks the same effect on top of itself.

When you double up like this, those side effects can become noticeably stronger, and in older folks confusion or a dangerously fast heartbeat is a real worry. This concern is based on how these compounds work rather than hard clinical studies, but the overlap is predictable enough that I would not combine them. Please check with your pharmacist or doctor before using Scopolia alongside Promazine.

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

Scopolia Also Interacts With Other Medications

Scopolia has 199 major, known drug interactions in our database — the Promazine 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 Scopolia

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

Everything else you take

See Every Supplement That Interacts With Promazine

This page covers Scopolia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promazine page lists 90 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Indian Snakeroot (major), Rauvolfia Vomitoria (major) and Alfalfa (moderate).

By severity: 5 major · 61 moderate · 24 minor.

From our pharmacist’s overview on the Promazine page

“Promazine (Sparine) is an older antipsychotic in the phenothiazine family, and the 90 supplements and herbs on this page deserve real attention before you add any of them. The biggest cluster, 30 ingredients, shares promazine's anticholinergic side effects, so pairing them can pile on dry mouth, constipation, and confusion; henbane car…”

Reviewed by 2 · Jul 18, 2026

Open the Promazine interaction page

How much people look this up

Where Scopolia and Promazine 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 Scopolia
Top half

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

29 days ago today
Medication Promazine
Steady interest

#2,805 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 Scopolia

What is Scopolia?

Scopolia
  • Stomach and intestinal cramps
  • Motion sickness
  • Spasms and colic
  • Excess saliva or secretions
  • Pain relief (traditional)

Scopolia is a poisonous plant in the nightshade family that contains powerful anticholinergic alkaloids like atropine, hyoscyamine, and scopolamine. While these compounds are used in carefully measured prescription medicines, the raw plant is dangerous for self-treatment and should never be used without a doctor's supervision.

Read the full Scopolia monograph & all interactions
Keep checking

Other Drugs & Scopolia

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

199Major
0Moderate
0Minor
2,630No known interaction
Major

199 interactions

Showing 60 of 199 major interactions — see all 199 on the Scopolia page.

No interaction 2,630 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 Scopolia and Promazine Together: Common Questions

Can you take Scopolia with Promazine?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Scopolia and Promazine interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or 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.