Drug & supplement interaction

Pheasant's Eye + Doxycycline monohydrate

Doxycycline monohydrate brand name: Erfacea.

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

Pheasant's Eye has a moderate interaction with Doxycycline monohydrate. Theoretically, taking pheasant's eye with tetracycline antibiotics might increase the risk of cardiac glycoside toxicity.

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

Pheasant's Eye and Doxycycline monohydrate

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

Moderate

TETRACYCLINE ANTIBIOTICS

Why this applies to Doxycycline monohydrate

Doxycycline monohydrate falls under TETRACYCLINE ANTIBIOTICS — the group Pheasant's Eye interacts with.

Theoretically, taking pheasant's eye with tetracycline antibiotics might increase the risk of cardiac glycoside toxicity.
Tetracycline antibiotics appear to increase the gastrointestinal absorption of oral digoxin. Theoretically, concomitant use of tetracycline antibiotics might increase the absorption of the cardiac glycosides found in pheasant's eye.
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 connection on file. Pheasant's Eye is a poisonous plant that contains heart-acting compounds (cardiac glycosides) much like the ones in digoxin. The thinking is that an antibiotic like doxycycline may change the gut bacteria that normally break down some of those heart compounds, which could let more of them get absorbed. In theory, that might nudge you toward cardiac glycoside toxicity, with things like nausea, a slow or irregular heartbeat, dizziness, or vision changes.

I want to be honest about the strength of this: it's theoretical, based on how these drugs behave, not on solid human studies. Doxycycline itself isn't the real danger here. The bigger issue is that Pheasant's Eye is toxic and unsafe to take on your own. Please don't use it without a doctor guiding you, and talk to your pharmacist if you're already combining the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.

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

Pheasant's Eye Also Interacts With Other Medications

Pheasant's Eye has 1 major, 154 moderate known drug interactions in our database — the Doxycycline monohydrate one above is one of them. If you take anything else, check it against the full list below.

Major 1 Moderate 154 No known interaction 2,675 (incl. Doxycycline monohydrate)
Taking anything else?

Check Another of Your Medications Against Pheasant's Eye

Covers the 2,830 medications we’ve checked against Pheasant's Eye. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Doxycycline monohydrate

This page covers Pheasant's Eye only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxycycline monohydrate page lists 166 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Oleander (major) and Siberian Cocklebur (major).

Open the Doxycycline monohydrate interaction page

How much people look this up

Where Pheasant's Eye and Doxycycline monohydrate 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 Pheasant's Eye
Steady interest

#1,098 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Doxycycline monohydrate
Top half

#1,182 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 Pheasant's Eye

What is Pheasant's Eye?

  • Heart failure symptoms
  • Irregular or weak heartbeat
  • Fluid retention (as a diuretic)
  • Nervous heart complaints
  • Mild anxiety with heart palpitations

Pheasant's Eye (Adonis vernalis) is a toxic plant that contains heart-acting compounds similar to those in foxglove. It has been used in traditional and old European medicine for heart problems, but it is poisonous and has a very narrow margin of safety. You should not use it on your own — it should only ever be considered under direct medical supervision, if at all.

Read the full Pheasant's Eye monograph & all interactions
Keep checking

Other Drugs & Pheasant's Eye

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

1Major
154Moderate
0Minor
2,674No known interaction
1 Major 154 Moderate 2,674 No interaction
Major

1 interaction

Moderate

154 interactions

Showing 60 of 154 moderate interactions — see all 154 on the Pheasant's Eye page.

No interaction 2,674 drugs checked — show the list

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

Showing the 60 most looked-up of 2,674 medications checked with no known interaction — see the full Pheasant's Eye list.

See the full Pheasant's Eye interactions page
See every supplement checked against Doxycycline monohydrate, 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
Pheasant's Eye monograph › Uses, safety, and every drug interaction in one place Doxycycline monohydrate supplement interactions › Every supplement checked against Doxycycline monohydrate, 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 Pheasant's Eye and Doxycycline monohydrate Together: Common Questions

Can you take Pheasant's Eye with Doxycycline monohydrate?
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 Pheasant's Eye and Doxycycline monohydrate 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

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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.