Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Wild Lettuce and Kava Kava Ingredients & Drug Interactions

by Herbal Terra

Wild Lettuce and Kava Kava label
See full label image
Liquid Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Wild Lettuce and Kava Kava against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Wild Lettuce and Kava Kava is a dietary supplement by Herbal Terra with 2 active ingredients. Its ingredients are commonly taken for insomnia and trouble sleeping, anxiety and restlessness, pain relief.Based on those ingredients, 1,243 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Kava Kava Root Extract, Dry, Wild Lettuce Herb Extract, Dry. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Wild Lettuce and Kava Kava by Herbal Terra

Ask about any prescription or over-the-counter medication and we check it for interactions with Wild Lettuce and Kava Kava by Herbal Terra — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Wild Lettuce and Kava Kava by Herbal Terra

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 2 active ingredients.
  • “Proprietary Extract Blend” is a proprietary blend — the label gives one combined amount (983 mg) without saying how much of each component you get.

This liquid contains 2 active ingredients: Wild Lettuce Herb Extract (dry form) and Kava Kava Root Extract (dry form), combined in a proprietary blend. Both are plant extracts—concentrated forms of the whole herb.

The product also contains alcohol, water, and glycerin as inactive ingredients (the carrier liquid and preservative system).

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

The label doesn't state a purpose we can grade — see each ingredient's own graded uses on its monograph instead.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold on these ingredients is sparse. For kava and generalized anxiety, the data actually rates it possibly ineffective—meaning studies haven't shown it works as intended for that use.

For kava's other traditional uses—insomnia, sexual arousal, and epilepsy—we don't have enough reliable evidence to rate whether it works or doesn't. Wild lettuce has no effectiveness ratings on file.

If you're considering this for a specific condition, that's worth discussing with your pharmacist or doctor.

The evidence, ingredient by ingredient Wild Lettuce Kava

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Wild lettuce is limited in human safety data, and large amounts have caused side effects: dizziness, ringing in the ears, vision problems, pressure in the head, drowsiness, and in extreme cases coma or respiratory depression. It's not recommended during pregnancy or while breastfeeding.

Kava is generally well tolerated at typical doses, with common mild side effects being drowsiness, dry mouth, dizziness, and headache. However, kava carries a rare but serious risk: over 100 cases of liver injury have been reported, especially with high doses or prolonged use; in susceptible people, liver damage can appear within 3–4 weeks.

Kava should be avoided during pregnancy and breastfeeding. If you have liver disease or take other liver-stressing medications, kava requires extra caution.

Side effects, ingredient by ingredient Wild Lettuce Kava

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — Wild Lettuce, Kava.
  • The most serious interaction on file is rated Major.
  • For scale: 1,244 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, double-check any sedative medications (sleeping pills, anti-anxiety drugs, opioids, antihistamines)—that's a Major interaction with kava alone. Also check medications metabolized by your liver (CYP2C19, CYP2C9, CYP2E1 substrates), antipsychotics like haloperidol, Parkinson's drugs like ropinirole, heart drugs like digoxin, anticholinergic medications, and any drug known to damage the liver.

The interaction checker below can screen all your medications at once.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This product combines two sedating herbs and is not suitable if you take any medications that make you drowsy—including sleep aids, antidepressants, anti-anxiety drugs, or opioids. Even if you don't take those, kava's documented liver injury risk and wide enzyme interactions mean you need to check your full medication list first.

Talk to your pharmacist before starting; they can run your drugs through the checker to make sure.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Dec 21, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Wild Lettuce and Kava Kava, straight from the product label.

Brand Herbal Terra
Barcode (UPC) 7439500934967
Net contents 2 Fluid Ounce(s); 60 mL
Market status On market
Date entered into DSLD Dec 21, 2024
DSLD ID 325512
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Wild Lettuce and Kava Kava by Herbal Terra, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 mL
Maximum serving Sizes:
1 mL
Servings per container
60
UPC/BARCODE
7439500934967
IngredientAmount% DV
Proprietary Extract Blend983 mg--
Wild Lettuce Herb Extract, Dry0 NP--
Kava Kava Root Extract, Dry0 NP--

Other ingredients: Alcohol, Water, Glycerin

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Shake well before use. Adults take up to 30 drops (1 mL, one full squeeze of the dropper bulb) in 3-4 fl. oz. of juice or water up to 4 times a day.

Precautions

We recommend to seek expert medical advice before taking. May have contraindications and cause adverse reaction.

Consult a physician before giving to children under 18, before using during pregnancy, if nursing, or if you are on any medications.

Consult a physician before giving to children under 18, before using during pregnancy, if nursing, or if you are on any medications. Keep out of the reach of children!

Do not use if you are allergic to any ingredients.

Storage

Store in a cool, dry, dark place.

FDA Disclaimer Statement

This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure or prevent any disease.

Formulation

cGMP Made in compliance with cGMP 21 CFR 111 in an FDA registered and inspected facility.

Sugar free

Expertly extracted 100% natural Premium product

Organic alcohol

No artificial ingredients, color additives, fillers or binders.

Natural Gluten free

Formula

Organic alcohol

FDA Statement of Identity

Herbal Supplement

General Statements

Extraction rate: about 1/ 3-4 (up to 333 mg of dry raw material per 1 ml of extract).

Seals/Symbols

Made in USA

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Wild Lettuce and Kava Kava by Herbal Terra label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Wild Lettuce and Kava Kava label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Wild Lettuce and Kava Kava by Herbal Terra

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 mL Dosage formLiquid Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Extract Blend

983 mg per serving

Other (inactive) ingredients: Alcohol, Water, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Wild Lettuce and Kava Kava by Herbal Terra Drug Interactions

Want to check YOUR meds against Wild Lettuce and Kava Kava?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,243Drugs
248 Major 695 Moderate 300 Minor

Ingredients driving the most interactions

Kava Kava Root Extract, Dry 1,166
Wild Lettuce Herb Extract, Dry 393

Individual Drug Interactions

The ingredients in Wild Lettuce and Kava Kava interact with 1,243 drugs. Click any drug to see the details.

2 of the 2 ingredients in Wild Lettuce and Kava Kava interact with drugs. Each result below shows which ingredient is responsible. Kava Kava Root Extract, Dry Wild Lettuce Herb Extract, Dry

Each ingredient & the kinds of drugs it affects

For each ingredient in Wild Lettuce and Kava Kava with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Kava Kava Root Extract, Dry12 drug types · 1,166 drugs

Cns Depressants

Combining kava with CNS depressants can have additive sedative effects.
Kava has CNS depressant effects. Concomitant use of kava with other CNS depressants can increase the risk of drowsiness and motor reflex depression. Clinical practice guidelines from a joint taskforce of the World Federation of Societies of Biological Psychiatry (WFSBP) and the Canadian Network for Mood and Anxiety Treatments (CANMAT) recommend that CNS depressants, including alcohol and benzodiazepines, not be used with kava.

Likelihood Probable Evidence A
Alcohol (Ethanol)

Combining kava with alcohol may increase the risk of sedation and/or hepatotoxicity.

Kava has CNS depressant effects. Concomitant use of kava with other CNS depressants can increase the risk of drowsiness and motor reflex depression. Additionally, kava has been associated with over 100 cases of hepatotoxicity. There is some concern that kava can adversely affect the liver, especially when used in combination with hepatotoxic drugs. Clinical practice guidelines from a joint taskforce of the World Federation of Societies of Biological Psychiatry (WFSBP) and the Canadian Network for Mood and Anxiety Treatments (CANMAT) recommend that alcohol not be used with kava.

Likelihood Possible Evidence A
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, kava might increase levels of CYP2C19 substrates.
In vitro research shows that kava significantly inhibits CYP2C19 enzymes. This effect has not yet been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, kava might increase levels of CYP2C9 substrates.
In vitro research shows that kava significantly inhibits CYP2C9 enzymes. This effect has not yet been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Kava might increase levels of CYP2E1 substrates.
In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days inhibited the metabolism of CYP2E1 substrates.

Likelihood Probable Evidence B
Haloperidol (Haldol)

Combining kava and haloperidol might increase the risk of cardiovascular adverse effects and hypoxia.
Atrial flutter and hypoxia has been reported for a patient who received intramuscular injections of haloperidol and lorazepam after using kava orally. The side effects were attributed to kava-induced inhibition of CYP2D6, but might also have been related to additive adverse effects with the concomitant use of haloperidol, lorazepam, and kava.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, using kava with hepatotoxic drugs might increase the risk of liver damage.
Kava has been linked with over 100 cases of hepatotoxicity. Most cases occur with excessive and prolonged use. There is some concern that kava can adversely affect the liver, especially when used in combination with hepatotoxic drugs.

Likelihood Possible Evidence D
P-Glycoprotein Substrates

It is unclear if kava inhibits P-glycoprotein (P-gp); research is conflicting.
In vitro research shows that kava can inhibit P-gp efflux. However, a clinical study in healthy volunteers shows that taking kava standardized to provide 225 mg kavalactones daily for 14 days does not affect the pharmacokinetics of digoxin, a P-gp substrate. It is possible that the use of other P-gp substrates or higher doses of kava might still inhibit P-gp.

Likelihood Possible Evidence D
Ropinirole (Requip)

Taking kava with ropinirole might increase the risk for dopaminergic toxicity.
A case of visual hallucinations and paranoid delusions has been reported for a patient who used kava in combination with ropinirole. The adverse effects were attributed to kava-induced inhibition of CYP1A2, which may have reduced the metabolism of ropinirole, resulting in excessive dopaminergic stimulation.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

It is unclear if kava inhibits CYP1A2; research is conflicting.
Although in vitro research and a case report suggest that kava inhibits CYP1A2, more robust clinical evidence shows that kava has no effect on CYP1A2. In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days had no effect on CYP1A2 activity.

Likelihood Unlikely Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

It is unclear if kava inhibits CYP1A2; research is conflicting.
In vitro research shows that kava extract significantly inhibits CYP2D6. However, clinical research shows that kava does not affect the metabolism of CYP2D6 substrates in humans.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

It is unclear if kava inhibits CYP3AA; research is conflicting.
Although in vitro research suggests that kava inhibits CYP3A4, more robust clinical evidence shows that kava has no effect on CYP3A4. In a clinical study in healthy volunteers, taking kava 1000 mg twice daily (containing a daily dose of 138 mg kavalactones) for 28 days had no effect on CYP3A4 activity.

Likelihood Unlikely Evidence B
Kava Kava Root Extract, Dry full monograph & interactions

Wild Lettuce Herb Extract, Dry2 drug types · 393 drugs

Anticholinergic Drugs

Studies report varying evidence on whether or not wild lettuce contains hyoscyamine, an anticholinergic drug. If it does, it appears to be in very low amounts. Nevertheless, there have been case reports of individuals consuming large amounts of wild lettuce experiencing anticholinergic-related side effects, such as constipation, dry mouth, dizziness, and sweating. Therefore, if you are already taking a drug with anticholinergic effects, you should be cautious about combining it with wild lettuce as the risk of side effects may be increased.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, concomitant use with drugs with sedative effects might cause additive therapeutic effects and adverse effects.

Likelihood Possible Evidence D
Wild Lettuce Herb Extract, Dry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Wild Lettuce and Kava Kava, from the product label.

Herbal Terra

See all Herbal Terra products
Name
Herbal Terra LLC
Phone Number
+18083857868
Web Address
herbalterra.com
Pharmacist Counseling Corner

Wild Lettuce and Kava Kava by Herbal Terra: Common Questions

Does Wild Lettuce and Kava Kava by Herbal Terra interact with any medications?
Yes. Based on its ingredients, Wild Lettuce and Kava Kava has a known interaction with 1,243 medications, including 248 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Wild Lettuce and Kava Kava contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is this safe to take during pregnancy or while breastfeeding?
No. Wild lettuce should be avoided during pregnancy due to insufficient safety data, and kava is not considered safe in pregnancy and should also be avoided while breastfeeding. If you're pregnant, nursing, or planning to become pregnant, don't use this product without talking to your doctor.
What are the most common side effects of kava?
The most common are drowsiness, dry mouth, dizziness, upset stomach, headache, memory problems, and tremor. These are usually mild, but tremor can be more pronounced—one trial found users had a 3-fold higher risk of tremors compared to placebo.
I've heard kava can damage the liver. How worried should I be?
It's a real concern but rare. Over 100 cases of liver injury have been reported worldwide, mostly with high doses or long-term use. In susceptible people it can happen within 3–4 weeks. If you have any liver disease or drink heavily, this product isn't for you. Otherwise, use only as directed and stop if you notice yellowed skin, dark urine, or abdominal pain.
Can I take this if I'm on a sleeping pill?
No, not safely. Both wild lettuce and kava are sedating, and combining them with sleep aids creates a Major risk of dangerous drowsiness and loss of motor control. You need to choose one or the other, and talk to your pharmacist before switching.
Does this product actually work for anxiety?
The evidence on kava for generalized anxiety is actually rated possibly ineffective—studies haven't shown it delivers the anxiety relief people hope for. Wild lettuce doesn't have effectiveness data on file. You may want to discuss other, better-studied options with your doctor.
What's in the liquid besides the herbs?
The product uses alcohol, water, and glycerin to carry and preserve the active extracts. If you need to avoid alcohol, this liquid form may not be right for you.

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

Not sure if Wild Lettuce and Kava Kava is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Wild Lettuce and Kava Kava label
Go deeper

The Full Monographs Behind Wild Lettuce and Kava Kava’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Wild Lettuce

Interacts with 393 drugs

Wild lettuce is a traditional herb used mainly for sleep, anxiety, and pain, but solid human research supporting these uses is very limited. Because its safety is not well studied, it should...

Read the full Wild Lettuce monograph → Herb & supplement monograph

Kava

Interacts with 1,166 drugs

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...

Read the full Kava monograph →
Sources

Sources & How We Checked

Wild Lettuce and Kava Kava's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 76 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Wild Lettuce 5 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009. pii: bcr06.2008.0134.
  5. Mullins ME, Horowitz BZ. The case of the salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40(5):290-1.

See these in context on the Wild Lettuce monograph →

Kava 71 references
  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.
  16. Liver Toxicity With Kava. Pharmacist's Letter/Prescriber's Letter. January 2001.
  17. Consultation letter MLX 286: Proposals to prohibit the herbal ingredient Kava-Kava (Piper methysticum) in unlicensed medicines. Medicines Control Agency, United Kingdom, July 19, 2002.
  18. Meseguer E, Taboada R, Sanchez V, et al. Life-threatening parkinsonism induced by kava-kava. Mov Disord 2002;17:195-6. PubMed
  19. Ruze P. Kava-induced dermopathy: a niacin deficiency? Lancet 1990;335:1442-5. PubMed
  20. Singh YN. Kava: an overview. J Ethnopharmacol 1992;37:13-45.
  21. Bilia AR, Gallori S, Vincieri FF. Kava-kava and anxiety: growing knowledge about the efficacy and safety. Life Sci 2002;70:2581-97. PubMed
  22. Wooltorton E. Herbal kava: reports of liver toxicity. CMAJ 2002;166:777.
  23. Mathews JM, Etheridge AS, Black SR. Inhibition of human cytochrome P450 activities by kava extract and kavalactones. Drug Metab Dispos 2002;30:1153-7. PubMed
  24. Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
  25. Teschke R, Gaus W, Loew D. Kava extracts: safety and risks including rare hepatotoxicity. Phytomedicine 2003;10:440-6. PubMed
  26. Schmidt P, Boehncke WH. Delayed-type hypersensitivity reaction to kava-kava extract. Contact Dermatitis 2000;42:363-4.
  27. Schulze J, Raasch W, Siegers CP. Toxicity of kava pyrones, drug safety and precautions--a case study. Phytomedicine 2003;10:68-73.. PubMed
  28. Pittler MH, Ernst E. Kava extract for treating anxiety. Cochrane Database Syst Rev 2003;(1):CD003383.
  29. Cairney S, Maruff P, Clough AR, et al. Saccade and cognitive impairment associated with kava intoxication. Hum Psychopharmacol 2003;18:525-33. PubMed
  30. Moulds RF, Malani J. Kava: herbal panacea or liver poison? Med J Aust 2003;178:451-3. PubMed
  31. Gow PJ, Connelly NJ, Hill RL, et al. Fatal fulminant hepatic failure induced by a natural therapy containing kava. Med J Aust 2003;178:442-3. PubMed
  32. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  33. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
  34. Weiss J, Sauer A, Frank A, Unger M. Extracts and kavalactones of Piper methysticum G. Forst (kava-kava) inhibit P-glycoprotein in vitro. Drug Metab Dispos 2005;33:1580-3. PubMed
  35. Gurley BJ, Swain A, Barone GW, et al. Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans. Drug Metab Dispos 2007;35:240-5. PubMed
  36. Gurley BJ, Swain A, Hubbard MA, et al. Clinical assessement of CYP2D6-mediated herb-drug interactions in humans: Effects of milk-thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea. Mol Nutr Food Res 2008;52:755-63.
  37. Li XZ, Ramzan I. Role of ethanol in kava hepatotoxicity. Phytother Res 2010;24:475-80. PubMed
  38. Bodkin R, Schneider S, Rekkerth D, et al. Rhabdomyolysis associated with kava ingestion. Am J Emerg Med 2012;30:635.el-3. PubMed
  39. Donadio V, Bonsi P, Zele I, et al. Myoglobinuria after ingestion of extracts of guarana, Ginkgo biloba and kava. Ginkgo biloba and kava. Neurol Sci 2000;21:124. PubMed
  40. 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
  41. Hannam S, Murray M, Romani L, Tuicakau M, J Whitfeld M. Kava dermopathy in Fiji: an acquired ichthyosis? Int J Dermatol 2014;53(12):1490-4. PubMed
  42. Huynh JC, Asgari MM, Moore MM. Sebotropic eruption associated with use of oral kava kava supplement. Clin Exp Dermatol 2014;39(7):816-8. PubMed
  43. Teschke R, Sarris J, Schweitzer I. Kava hepatotoxicity in traditional and modern use: the presumed Pacific kava paradox hypothesis revisited. Br J Clin Pharmacol 2012;73(2):170-4. PubMed
  44. Scherer, J. Kava-kava extract in anxiety disorders: an outpatient observational study. Adv.Ther. 1998;15(4):261-269.
  45. Humberston, C. L., Akhtar, J., and Krenzelok, E. P. Acute hepatitis induced by kava kava. J Toxicol.Clin Toxicol. 2003;41(2):109-113. PubMed
  46. Schmidt, M. Are kavalactones the hepatotoxic principle of kava extracts? The pitfalls of the glutathione theory. J Altern Complement Med 2003;9(2):183-187. PubMed
  47. Stickel, F., Baumuller, H. M., Seitz, K., Vasilakis, D., Seitz, G., Seitz, H. K., and Schuppan, D. Hepatitis induced by Kava (Piper methysticum rhizoma). J Hepatol. 2003;39(1):62-67. PubMed
  48. Grace, R. Kava-induced urticaria. J Am Acad Dermatol 2005;53(5):906. PubMed
  49. Christl, S. U., Seifert, A., and Seeler, D. Toxic hepatitis after consumption of traditional kava preparation. J.Travel.Med. 2009;16(1):55-56. PubMed
  50. Teschke, R., Genthner, A., and Wolff, A. Kava hepatotoxicity: comparison of aqueous, ethanolic, acetonic kava extracts and kava-herbs mixtures. J.Ethnopharmacol. 6-25-2009;123(3):378-384. PubMed
  51. Jappe, U., Franke, I., Reinhold, D., and Gollnick, H. P. Sebotropic drug reaction resulting from kava-kava extract therapy: a new entity? J Am Acad Dermatol. 1998;38(1):104-106. PubMed
  52. Gessner B and Cnota P. Extract of the kava-kava rhizome in comparison with diazepam and placebo. Z Phytother 1994;15(1):30-37.
  53. Johnson D, Frauendorf A, Stecker K, and et al. Neurophysiological active profile and tolerance of kava extract WS 1490, A pilot study with randomized evaluation. TW Neurolgie Psychiatrie 1991;5(6):349-354.
  54. Keller F and Klohs M. A review of the chemistry and pharmacology of the constituents of Piper methysticum. Lloydia 1963;26:1-15.
  55. Siegers CP, Honold E, Krall B, and et al. Results of the drug monitoring L 1090 with Laitan capsules. Arztl Forsch 1992;39:7-11.
  56. Chanwai, L. G. Kava toxicity. Emergency Medicine 2002;12:142-145.
  57. Leung, N. Acute urinary retention secondary to kava ingestion. Emerg Med Australas 2004;16(1):94. PubMed
  58. Teschke R. Kava hepatotoxicity: pathogenetic aspects and prospective considerations. Liver Int 2010;30(9):1270-9. PubMed
  59. Toohey TP, Lu BY, Wada C. Toxic effects of psychotropics related to possible p450 enzyme inhibition by kava:report of 2 cases. Prim Care Companion CNS Disord 2013;15(5). PubMed
  60. Ostermayer D. News: Kava, Popular as Alcohol Alternative, May Cause Toxicity. Emerg Med News. 2016;38(1B).
  61. Kuchta K, Schmidt M, Nahrstedt A. German Kava Ban Lifted by Court: The Alleged Hepatotoxicity of Kava (Piper methysticum) as a Case of Ill-Defined Herbal Drug Identity, Lacking Quality Control, and Misguided Regulatory Politics. Planta Med. 2015;81(18):16 PubMed
  62. Schmidt M. German Court Ruling Reverses Kava Ban; German Regulatory Authority Appeals Decision. HerbalEGram. 2014;11(7).
  63. Wainiqolo I, Kool B, Nosa V, Ameratunga S. Is driving under the influence of kava associated with motor vehicle crashes? A systematic review of the epidemiological literature. Aust N Z J Public Health 2015;39(5):495-9. PubMed
  64. Wainiqolo I, Kafoa B, Kool B, et al. Driving following kava use and road traffic injuries: a population-based case-control study in Fiji (TRIP 14). PLoS One 2016;11(3):e0149719. PubMed
  65. Asher GN, Corbett AH, Hawke RL. Common Herbal Dietary Supplement-Drug Interactions. Am Fam Physician. 2017;96(2):101-107.
  66. Sarris J, Byrne GJ, Bousman CA, et al. Kava for generalised anxiety disorder: A 16-week double-blind, randomised, placebo-controlled study. Aust N Z J Psychiatry. 2020 Mar;54(3):288-297. PubMed
  67. Aporosa AS, Atkins M, Brunton R. Kava drinking in traditional settings: towards understanding effects on cognitive function. Hum Psychopharmacol. 2020;35(2):e2725. PubMed
  68. Sarris J, Ravindran A, Yatham LN, et al. Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety T
  69. Aporosa S', Ballard H, Pandey R, McCarthy MJ. The impact of traditional kava (Piper methysticum) use on cognition: Implications for driver fitness. J Ethnopharmacol 2022;291:115080. PubMed
  70. Savage K, Sarris J, Hughes M, et al. Neuroimaging insights: Kava's (Piper methysticum) effect on dorsal anterior cingulate cortex GABA in generalized anxiety disorder. Nutrients 2023;15(21):4586. PubMed
  71. du Plessis Nisbet J, Xie D, Thompson R, Wark K, Lamrock E, Scurry J. Kava-induced dermatitis: A detailed histopathological analysis. Australas J Dermatol 2024. PubMed

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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.

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