Drug & supplement interaction

Squill + Tigecycline

Tigecycline brand name: Tygacil.

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

Tigecycline falls into 2 drug categories that Squill can interact with; the most serious is rated moderate. Macrolide antibiotics appear to increase the gastrointestinal absorption of oral digoxin.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Squill and Tigecycline

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Squill interacts with whole categories of medication. Tigecycline falls into 2 of those categories, so it can interact with Squill in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

MACROLIDE ANTIBIOTICS

1 of 2

Why this applies to Tigecycline

Tigecycline falls under MACROLIDE ANTIBIOTICS — the group Squill interacts with.

Macrolide antibiotics appear to increase the gastrointestinal absorption of oral digoxin. Theoretically, concomitant use of macrolide antibiotics might increase the absorption of the cardiac glycosides found in squill.
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 idea behind this one. Squill contains natural cardiac glycosides that act on the heart a lot like digoxin. Certain antibiotics may increase how much of these heart-active compounds your gut absorbs, so the worry is that pairing them could push squill's effects higher than expected. With more squill in your system, you could see things like nausea, a slow or irregular heartbeat, or palpitations.

I'll be honest with you though: this flag comes from how related antibiotics behave with digoxin, not from direct testing with tigecycline. It's theoretical. Tigecycline is a tetracycline-type antibiotic, not a prodrug, so it isn't activated or blocked here. The bigger point is that squill itself is potent and risky, so please don't take it without talking to your doctor or pharmacist first.

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.
Moderate

TETRACYCLINE ANTIBIOTICS

2 of 2

Tigecycline also falls under TETRACYCLINE ANTIBIOTICS.

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 squill.
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 idea behind this pairing. Squill contains natural heart-affecting compounds called cardiac glycosides, which behave a lot like the prescription drug digoxin. We know tetracycline antibiotics can boost how much digoxin your gut absorbs, so on paper, Tygacil (tigecycline) might let your body take in more of squill's heart-active compounds. More of those getting into your system could mean a stronger, harder-to-control effect on your heart rhythm and heartbeat, which can be dangerous since squill is toxic to begin with.

I'll be honest: this is a theoretical concern based on how these drugs work, not something proven in studies. Still, given how potent squill is, I would not combine the two on your own. Please run it by your doctor or pharmacist first.

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

Squill Also Interacts With Other Medications

Squill has 1 major, 154 moderate known drug interactions in our database — the Tigecycline one above is among them. If you take anything else, check it against the full list below.

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

Check Another of Your Medications Against Squill

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

Everything else you take

See Every Supplement That Interacts With Tigecycline

This page covers Squill only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tigecycline page lists 98 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Oleander (major), Para-aminobenzoic Acid (paba) (major), Acerola (moderate), Alfalfa (moderate) and Alpha-lipoic Acid (moderate).

By severity: 2 major · 88 moderate · 8 minor.

From our pharmacist’s overview on the Tigecycline page

“Tigecycline (Tygacil) is an intravenous antibiotic usually reserved for serious or resistant infections, and its supplement list deserves real attention. The two major-rated entries come first: oleander, a heart-toxic plant whose compounds may build to dangerous levels with certain antibiotics on board, and PABA, which can blunt the an…”

Reviewed by 2 · Jul 18, 2026

Open the Tigecycline interaction page

One more smart check

Taking Squill as Part of a Dietary Supplement Product? Check It for Interactions

We hold 2 real supplement products containing Squill, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Squill. Your product may carry other ingredients that interact with Tigecycline too, on top of Squill — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Squill and Tigecycline 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 Squill
Top half

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

29 days ago today
Medication Tigecycline
Steady interest

#2,202 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 Squill

What is Squill?

Squill
  • Cough and chest congestion
  • Fluid retention (diuretic)
  • Heart conditions (traditional 'cardiac tonic')
  • Hair loss (topical use)
  • Rodenticide (red squill, non-medicinal)

Squill is a bulb plant that contains potent cardiac glycosides, which can affect the heart much like the drug digoxin. While it has a long history of use as a cough remedy and heart tonic, it can be dangerously toxic and there is little solid evidence for its modern use, so we do not recommend taking it without close medical supervision.

Read the full Squill monograph & all interactions
Medication

About Tigecycline Injection

What Is Tigecycline Injection Used For?

Brand name: Tygacil

Tygacil (tigecycline for injection) is approved for adults 18 and older to treat three types of serious bacterial infections: complicated skin and skin structure infections, complicated intra-abdominal (stomach and intestinal) infections, and community-acquired bacterial pneumonia (pneumonia caught outside a hospital).

It is not approved for diabetic foot infections or for pneumonia caught in a hospital setting, including ventilator-associated pneumonia — clinical trials showed it did not work well enough for those uses and was associated with higher mortality in patients with ventilator-associated pneumonia.

See full Tigecycline Injection drug information
Keep checking

Other Drugs & Squill

Browse every other medication we’ve checked against Squill — 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 Squill page.

No interaction 2,674 drugs checked — show the list

We also checked Squill 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 Squill list.

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

Can you take Squill with Tigecycline?
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.
Why are there 2 interactions listed for Squill and Tigecycline?
Tigecycline belongs to more than one drug category, and Squill interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Squill and Tigecycline 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

Still Have a Question About Tigecycline and Squill?

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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.