Drug & supplement interaction

Pyrethrum + Ribavirin Aerosol

Ribavirin Aerosol brand name: Virazole.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Pyrethrum and Ribavirin Aerosol 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. Additionally, although there is no interaction, the label for Ribavirin Aerosol states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Pyrethrum and Ribavirin Aerosol

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 Ribavirin Aerosol and Pyrethrum 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 Pyrethrum at all — not against Ribavirin Aerosol, 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.

Pyrethrum safety at a glance

Pyrethrum overall Use caution Pyrethrum is an insecticide, not a dietary supplement, and should not be taken internally.
Pregnancy Avoid Avoid internal use and limit exposure to insecticide products during pregnancy due to lack of safety data.
Breastfeeding Avoid Avoid internal use while breastfeeding because safety has not been established.

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

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

No Interaction Found — But Data Suggests Pyrethrum and Ribavirin Aerosol May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Nausea / Headache reported in 11.6% of FDA reports for Ribavirin Aerosol Additional detail

    Pyrethrum

    “Pyrethrum has limited toxicity. The symptoms of overdose include headache, tinnitus, nausea, tingling of fingers and toes, respiratory disturbances, and other symptoms of neurotoxicity (18). The pyrethrum flower or derivatives of it might cause an allergic reaction in individuals sensitive to the Asteraceae/Compositae family.”

    Pyrethrum · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Ribavirin Aerosol

    Listed in the ADVERSE REACTIONS section of the FDA label for Ribavirin Aerosol, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Pyrethrum but not commonly for Ribavirin Aerosol: an allergic reaction, numbness or tingling and ringing in the ears.

Effects for Ribavirin Aerosol come from the ADVERSE REACTIONS section of its FDA label; effects for Pyrethrum come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 63,877 voluntary FDA FAERS reports for Ribavirin Aerosol that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Ribavirin Aerosol Products Have a Food Rule — Pyrethrum Should Not Break It

At least one FDA label for a product containing Ribavirin Aerosol says to take it with food. If you take Pyrethrum on an empty stomach out of habit, keep them separate — and take Ribavirin Aerosol with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Ribavirin Aerosol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Ribavirin capsules should be taken with food [see Clinical Pharmacology (12.3) ].

From the Dosage and Administration section of the FDA label we read for Ribavirin Aerosol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Ribavirin Aerosol

This page covers Pyrethrum only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ribavirin Aerosol page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Ribavirin Aerosol page

“Ribavirin Aerosol (Virazole) is an inhaled antiviral used mostly in hospitals against severe RSV infection, and with an infection that serious, losing drug exposure is not a small problem, so I would approach this list with genuine care. Its one major-rated interaction, activated charcoal, can pull ribavirin out of the body even though…”

Reviewed by 2 · Jul 18, 2026

Open the Ribavirin Aerosol interaction page

How much people look this up

Where Pyrethrum and Ribavirin Aerosol 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 Pyrethrum
Steady interest

#1,124 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ribavirin Aerosol
Top 25%

#393 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.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Pyrethrum reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Pyrethrum and Ribavirin Aerosol records this page draws on were last updated July 10, 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 Pyrethrum

What is Pyrethrum?

  • Natural insect repellent
  • Killing fleas, lice, and other pests
  • Garden and household insecticide
  • Traditional use against parasites

Pyrethrum is a daisy-like flower whose extracts (called pyrethrins) are widely used as a natural insecticide for plants, pets, and lice. It is not a supplement meant to be taken by mouth, and there is no good evidence supporting any internal health use. If you use pyrethrum products, treat them as pesticides and follow label directions carefully.

Tanacetum cinerariifolium · Asteraceae · Dried flower heads · Insecticide powders, sprays, and extracts (pyrethrins); rarely used internally

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

Pyrethrum: dosing

There is no established or recommended internal dose for pyrethrum, and it should not be taken as a supplement. For insecticide, lice, or flea products, the correct amount depends entirely on the specific product.Always follow the directions on the product label exactly, and do not use more or more often than directed.

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

Read the full Pyrethrum monograph & all interactions
Medication

About Ribavirin

What Is Ribavirin Used For?

Brand name: Virazole

Ribavirin comes in different forms for different uses. Ribavirin capsules are used in combination with interferon alfa-2b (pegylated or non-pegylated) to treat chronic hepatitis C (CHC) in patients 3 years and older with compensated liver disease. Ribavirin tablets are used in combination with PEGASYS® (peginterferon alfa-2a) to treat chronic hepatitis C in patients 5 years and older with compensated liver disease who have not previously been treated with interferon — including adults who also have HIV. Ribavirin for inhalation solution is a separate product used to treat hospitalized infants and young children with severe lower respiratory tract infections caused by respiratory syncytial virus (RSV).

Ribavirin must never be used alone to treat hepatitis C — it only works as part of combination therapy. Only the most severe RSV infections requiring hospitalization should be treated with the inhaled form; mild RSV illness in children does not require this treatment.

See full Ribavirin drug information
Keep checking

Other Drugs & Pyrethrum

Browse every other medication we’ve checked against Pyrethrum — 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

Pyrethrum References

The 3 references that drive our Pyrethrum monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  2. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  3. Drugs in Pregnancy and Lactation. 4th ed. Baltimore, MD: Williams & Wilkins, 1994.

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 Pyrethrum and Ribavirin Aerosol Together: Common Questions

Is it safe to take Pyrethrum with Ribavirin Aerosol?
We do not list a known interaction between Pyrethrum and Ribavirin Aerosol. 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.
Do Pyrethrum and Ribavirin Aerosol have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Pyrethrum and Ribavirin Aerosol at the same time of day?
At least one FDA label for a product containing Ribavirin Aerosol says to take it with food. If you take Pyrethrum on an empty stomach out of habit, keep them separate and take Ribavirin Aerosol with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Ribavirin Aerosol products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Ribavirin Aerosol interact with any supplements?
Yes. Ribavirin Aerosol has documented interactions with 17 supplements in our database — Pyrethrum is not one of them. The Ribavirin Aerosol 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 Ribavirin Aerosol and Pyrethrum?

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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.