Drug & supplement interaction

Kava + Zanamivir

Zanamivir brand name: Relenza.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 27, 2026
The bottom line No known interaction

We found no known interaction between Kava and Zanamivir 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 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

Kava and Zanamivir

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 Zanamivir and Kava 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.

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.

Kava safety at a glance

Kava overall Use caution Kava may help anxiety but has been linked to rare, serious liver injury and is banned or restricted in some countries.
Pregnancy Avoid Kava is not considered safe during pregnancy and should be avoided.
Breastfeeding Possibly Unsafe When used orally. There is concern that the toxic pyrone constituents of kava can pass into breast milk; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Zanamivir and Kava? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Zanamivir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Zanamivir is filed under a single classification — oral drugs. Kava has documented interactions with 12 drug classes — the most serious being cns depressants (major), alcohol (ethanol) (moderate) and cytochrome p450 2c19 (cyp2c19) substrates (moderate) — and none of Zanamivir’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Kava Does Interact With Other Medications

Kava has 248 major, 577 moderate, 341 minor known drug interactions in our database — Zanamivir isn’t one of them. If you take anything else, check it against the full list below.

Major 248 Moderate 577 Minor 341 No known interaction 1,664 (incl. Zanamivir)
Taking anything else?

Check Another of Your Medications Against Kava

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

What to actually watch for

No Interaction Found — But Data Suggests Kava and Zanamivir 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.

  • Dizziness / Headache Additional detail

    Kava

    “Orally, kava may cause headache, dizziness, and drowsiness. It might also cause extrapyramidal side effects such as involuntary oral and lingual reflexes, twisting movements of the head and trunk, tremors, and other parkinsonian-like symptoms possibly due to dopamine antagonism.”

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

    6 sources cited
    1. 4032. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed
    2. 6402. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
    3. 11370. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.
    4. 11372. Pittler MH, Ernst E. Kava extract for treating anxiety. Cochrane Database Syst Rev 2003;(1):CD003383.
    5. 11373. Cairney S, Maruff P, Clough AR, et al. Saccade and cognitive impairment associated with kava intoxication. Hum Psychopharmacol 2003;18:525-33. PubMed
    6. 18316. Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed

    Zanamivir

    Listed in the ADVERSE REACTIONS section of the FDA label for Zanamivir. Read the label on DailyMed ›

  • Nausea Additional detail

    Kava

    “Orally, kava may cause gastrointestinal upset, nausea, or dry mouth.”

    Kava · Natural Medicines adverse-effect record, reported in dry mouth.

    6 sources cited
    1. 2093. Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol 2000;20:84-9. PubMed
    2. 2094. Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders--a randomized placebo-controlled 25-week outpatient trial. Pharmacopsychiatry 1997;30:1-5. PubMed
    3. 4032. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed
    4. 11370. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.
    5. 18316. Sarris J, Kavanagh DJ, Byrne G, et al. The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Psychopharmacology 2009;205:399-407. PubMed
    6. 57228. Scherer, J. Kava-kava extract in anxiety disorders: an outpatient observational study. Adv.Ther. 1998;15(4):261-269.

    Zanamivir

    Listed in the ADVERSE REACTIONS section of the FDA label for Zanamivir. Read the label on DailyMed ›

Reported for Kava but not commonly for Zanamivir: stomach upset, shortness of breath, a low platelet count and memory problems.

Effects for Zanamivir come from the ADVERSE REACTIONS section of its FDA label; effects for Kava come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Kava in Pregnancy & Breastfeeding

Lactation Possibly Unsafe

When used orally. There is concern that the toxic pyrone constituents of kava can pass into breast milk; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Zanamivir

This page covers Kava only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Zanamivir 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 Zanamivir page

“Activated charcoal is the single entry I would want anyone on zanamivir (Relenza) to understand first. It holds the one major rating among the 17 supplements known to interact, because charcoal binds many drugs and can lower how much reaches the body, even when a medicine is not swallowed.”

Reviewed by 2 · Jul 18, 2026

Open the Zanamivir interaction page

One more smart check

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

We hold 403 real supplement products containing Kava, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Kava. Even though Kava itself has no known interaction with Zanamivir, 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 Kava and Zanamivir 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 Kava
Top 25%

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

29 days ago today
Medication Zanamivir
Steady interest

#1,711 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 Kava reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Kava and Zanamivir records this page draws on were last updated July 11, 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 Kava

What is Kava?

Kava
  • Anxiety and stress
  • Restlessness
  • Trouble sleeping
  • Relaxation in social or cultural settings
  • Menopausal symptoms

Kava is a Pacific Island plant traditionally used to promote relaxation and ease anxiety, and some studies suggest it may help mild anxiety. However, kava has been linked to rare but serious liver damage, so it should be used with caution, avoided by people with liver problems, and only used after talking with your pharmacist or doctor.

Piper methysticum · Piperaceae · Roots and rhizomes · Capsules, tablets, liquid extracts, tinctures, teas, and traditional water-based root drinks

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

Kava: dosing

There is no single established or standardized dose for kava, and products vary widely in how much kavalactone they contain. Because of this and the risk of liver harm, it is best not to guess at a dose on your own.If you and your healthcare provider decide kava is appropriate, follow the directions on the product label and use the lowest effective amount for the shortest time. Many experts advise limiting how long you use kava.

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

Read the full Kava monograph & all interactions
Medication

About Zanamivir Oral Inhalation

What Is Zanamivir Oral Inhalation Used For?

Brand name: Relenza

Relenza (zanamivir) inhalation powder is used to treat uncomplicated, acute influenza A and B in adults and children aged 7 and older — but only when symptoms have been present for no more than 2 days. The sooner treatment starts, the better.

Relenza is also used to help prevent (prophylax) influenza in adults and children aged 5 and older, including in household settings where someone is sick and in broader community outbreaks. It is not a substitute for your annual flu vaccine, and it has not been shown to prevent influenza in nursing home residents.

Most-Reported Side Effects for Zanamivir

From FAERS, the FDA’s public side-effect reporting system (2,524 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Abnormal behaviour 398 reports
Overdose 395 reports
Drug exposure during pregnancy 244 reports
Hallucination 159 reports
Drug exposure via breast milk 123 reports
See full Zanamivir Oral Inhalation drug information
Keep checking

Other Drugs & Kava

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

248Major
577Moderate
341Minor
1,663No known interaction
248 Major 577 Moderate 341 Minor 1,663 No interaction
Major

248 interactions

Showing 60 of 248 major interactions — see all 248 on the Kava page.

Moderate

577 interactions

Showing 60 of 577 moderate interactions — see all 577 on the Kava page.

Minor

341 interactions

Showing 60 of 341 minor interactions — see all 341 on the Kava page.

No interaction 1,663 drugs checked — show the list

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

Showing the 60 most looked-up of 1,663 medications checked with no known interaction — see the full Kava list.

See the full Kava interactions page
See every supplement checked against Zanamivir, ranked by severity
Evidence & sources

Kava References

The 71 references that drive our Kava 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. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Strahl S, Ehret V, Dahm HH, Maier KP. [Necrotizing hepatitis after taking herbal medication]. Dtsch Med Wochenschr 1998;123:1410-4.
  3. Spillane PK, et al. Neurological manifestations of kava intoxication. Med J Aust 1997;167:172-3. PubMed
  4. Swensen JN. Man convicted of driving under the influence of kava. Salt Lake City, UT: Deseret News, 1996.
  5. Pittler MH, Ernst E. Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol 2000;20:84-9. PubMed
  6. Volz HP, Kieser M. Kava-kava extract WS 1490 versus placebo in anxiety disorders--a randomized placebo-controlled 25-week outpatient trial. Pharmacopsychiatry 1997;30:1-5. PubMed
  7. Heinze HJ, Munthe TF, Steitz J, Matzke M. Pharmacopsychological effects of oxazepam and kava-extract in a visual search paradigm assessed with event-related potentials. Pharmacopsychiatry 1994;27:224-30. PubMed
  8. Munte TF, Heinze HJ, Matzke M, Steitz J. Effects of oxazepam and an extract of kava roots (Piper methysticum) on event-related potentials in a word recognition task. Neuropsychobiology 1993;27:46-53.
  9. Wheatley D. Stress-induced insomnia treated with kava and valerian: singly and in combination. Hum Psychopharmacol 2001;16:353-6. PubMed
  10. Schelosky L, Raffaup C, Jendroska K, Poewe W. Kava and dopamine antagonism. J Neurol Neurosurg Psychiatry 1995;58:639-40. PubMed
  11. Norton SA, Ruze P. Kava dermopathy. J Am Acad Dermatol 1994;31:89-97.
  12. Pizzorno JE, Murray MT, eds. Textbook of Natural Medicine. 2nd ed. Edinburgh:Churchill Livingstone, 1999.
  13. Mathews JD, Riley MD, Fejo L, et al. Effects of heavy usage of kava on physical health: Summary of a pilot survey in an aboriginal community. Med J Aust 1988;148:548-55.
  14. Escher M, Desmeules J, Giostra E, Mentha G. Hepatitis associated with Kava, a herbal remedy for anxiety. BMJ 2001;322:139.
  15. Russmann S, Lauterburg BH, Helbling A. Kava hepatotoxicity [letter]. Ann Intern Med 2001;135:68-9.

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 Kava and Zanamivir Together: Common Questions

Is it safe to take Kava with Zanamivir?
We do not list a known interaction between Kava and Zanamivir. 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 Kava and Zanamivir have any of the same side effects?
Yes — our sources link each of them separately to 3 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.
How was the Kava and Zanamivir combination checked?
Interactions in our licensed database are recorded against drug classes. Zanamivir is filed under 1 classification, and Kava has documented interactions with 12 drug classes — none of Zanamivir's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Kava interact with any other medications?
Yes. Kava has 1,166 documented drug interactions in our database — Zanamivir is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Zanamivir interact with any supplements?
Yes. Zanamivir has documented interactions with 17 supplements in our database — Kava is not one of them. The Zanamivir interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Kava monograph Uses, safety profile, and every drug interaction in one place Zanamivir Oral Inhalation drug information The full plain-English guide to this medication Zanamivir supplement interactions Every supplement checked against Zanamivir, 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 References The 71 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Zanamivir and Kava?

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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.