Drug & supplement interaction

Poplar + Nafcillin

Nafcillin brand name: Nallpen.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Poplar and Nafcillin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Poplar and Nafcillin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Nafcillin and Poplar in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Poplar at all — not against Nafcillin, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Poplar safety at a glance

Poplar overall Use caution Generally used in folk medicine, but human safety data are limited and it contains aspirin-like compounds.
Pregnancy Avoid Not enough safety data and its salicylate content makes it best avoided during pregnancy.
Breastfeeding Avoid Safety during breastfeeding is unknown, so it is best avoided.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Nafcillin and Poplar? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Nafcillin’s Own FDA Label Lists

This is not an interaction — none of it involves Poplar. These are the most notable effects listed in the ADVERSE REACTIONS section of Nafcillin’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on mentioned in 21.2% of FDA reports for Nafcillin
  • Blood clots Worth acting on
  • Wheezing Worth acting on
  • A severe allergic reaction Worth acting on
  • Hives Worth acting on
  • A low white blood cell count Worth acting on
  • An allergic reaction Worth acting on
  • Mouth irritation or sores
  • Fever mentioned in 4.8% of FDA reports for Nafcillin
  • Low blood pressure

Showing the 10 most notable of 20 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Nafcillin. Read the label on DailyMed › Where a percentage is shown, it is the share of 918 voluntary FDA FAERS reports for Nafcillin that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Poplar’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Poplar side to compare — that is a limit of the record, not a statement that Poplar has no side effects.

Everything else you take

See Every Supplement That Interacts With Nafcillin

This page covers Poplar only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nafcillin page lists 58 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Asarabacca (major), Siberian Cocklebur (major), Alkanna (moderate), Alpine Ragwort (moderate) and Aristolochia (moderate).

By severity: 2 major · 54 moderate · 2 minor.

From our pharmacist’s overview on the Nafcillin page

“Anyone on nafcillin (Nallpen) is usually fighting a serious staph infection, and that makes this a time to be genuinely careful with supplements. Of the 58 with a known interaction on file, the two rated major, Siberian cocklebur and asarabacca, both stress the kidneys and could compound damage while you are being treated.”

Reviewed by 2 · Jul 18, 2026

Open the Nafcillin interaction page

One more smart check

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

We hold 4 real supplement products containing Poplar, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Poplar. Even though Poplar itself has no known interaction with Nafcillin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Poplar and Nafcillin 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 Poplar
Steady interest

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

29 days ago today
Medication Nafcillin
Steady interest

#2,647 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions. Poplar is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Poplar reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Poplar and Nafcillin records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Poplar

What is Poplar?

  • Minor pain and fever
  • Arthritis and joint discomfort
  • Minor skin wounds and irritation (topical)
  • Coughs and sore throat
  • Inflammation

Poplar comes from trees in the Populus genus and has a long history in folk medicine for pain, inflammation, and minor wounds, partly because its bark and buds contain salicin (a salicylate similar to the building block of aspirin). High-quality human studies are limited, so its true effectiveness is uncertain. Talk with your pharmacist or doctor before using it, especially if you are sensitive to aspirin.

Populus spp. · Salicaceae · Bark, leaf buds (leaf bud resin), and leaves · Tea, tincture, capsules, topical salves and ointments, dried bark or buds

An interaction check asks whether these two react with each other — it does not ask whether Poplar is a good idea for someone in your situation. Here is what our Poplar record says about it on its own.

Poplar: dosing

There is no well-established standard dose for poplar. The right amount depends on the product, the part of the plant used, and how it is prepared (tea, tincture, capsule, or topical).The safest approach is to follow the directions on the product label and not exceed them.

From our Poplar monograph — the full record covers uses, side effects and every documented interaction.

Read the full Poplar monograph & all interactions
Medication

About Nafcillin Injection

What Is Nafcillin Injection Used For?

Brand name: Nallpen

NAFCILLIN Injection is used to treat infections caused by staphylococci — specifically strains that produce an enzyme called penicillinase, which makes them resistant to regular penicillin. Susceptibility testing is performed to confirm the bacteria will respond to nafcillin before or shortly after starting treatment.

Nafcillin may also be started right away when a resistant staph infection is strongly suspected, even before test results are available. It should not be used for infections caused by bacteria that would respond to standard penicillin G, or for infections caused by non-staph organisms.

Most-Reported Side Effects for Nafcillin

From FAERS, the FDA’s public side-effect reporting system (918 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Renal failure acute 64 reports
Rash 56 reports
Acute kidney injury 49 reports
Fever 44 reports
Tubulointerstitial nephritis 43 reports
See full Nafcillin Injection drug information
Keep checking

Other Drugs & Poplar

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Poplar References

The 2 sources that drive our Poplar monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Poplar is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Salicylate Sensitivity — MedlinePlus Source
  2. Herbs at a Glance — NIH NCCIH Source

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Poplar and Nafcillin Together: Common Questions

Is it safe to take Poplar with Nafcillin?
We do not list a known interaction between Poplar and Nafcillin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Nafcillin interact with any supplements?
Yes. Nafcillin has documented interactions with 58 supplements in our database — Poplar is not one of them. The Nafcillin interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Nafcillin and Poplar?

Our pharmacists answer your medication & supplement questions — free.

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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.