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What laboratory studies, small human studies and case reports actually show about kava interactions.

Kort og Konsist

Kava can interact with medicines and other central nervous system depressants. Laboratory findings show several possible CYP inhibitions, but small human studies do not confirm one uniform pattern across all enzymes. Alcohol and sedatives in particular should not be self-combined; regular medication warrants individual review.

CYP450-systemet

CYP450-systemet (CYP450) er en familie av enzymer i leveren som er ansvarlige for nedbrytning av de fleste legemidler. Når et stoff hemmer disse enzymene, nedbrytes andre stoffer langsommere – deres virkning og bivirkninger kan dermed forsterkes.

Hvorfor er dette viktig?

Many medicines are metabolised by CYP enzymes. An in-vitro finding does not automatically mean clinically relevant inhibition in humans. Preparation, dose, duration and the medicine's therapeutic window determine practical relevance.

Hvilke enzymer hemmer?

Mathews et al. (2002) tested kava extract and individual kavalactones in human liver microsomes and found inhibition of several CYP enzymes. These are in-vitro findings, not clinical inhibition ratings in humans:

EnzymHemmestyrkeViktige substrater (eksempler)
CYP1A2In-vitro findingKoffein, teofyllin, klozapin, olanzapin
CYP2C9In-vitro findingWarfarin, fenytoin, NSAIDs (ibuprofen)
CYP2C19In-vitro findingOmeprazol, diazepam, klopidogrel
CYP2D6In-vitro findingKodein, tramadol, mange antidepressiva
CYP3A4In-vitro findingBenzodiazepiner, statiner, mange antibiotika

Klinisk betydning

Russmann et al. (2005) reported reduced CYP1A2 activity in chronic users of traditional aqueous kava. Gurley et al. (2005; 12 healthy volunteers, 28 days, 138 mg kavalactones/day), by contrast, found reduced CYP2E1 but no significant change in CYP1A2, CYP2D6 or CYP3A4/5. The human findings are small and preparation- and consumption-dependent, so they cannot predict every medicine interaction.

Høyrisiko-kombinasjoner

The following combinations should be avoided or medically reviewed in advance. Reasons differ: some involve additive CNS effects or case reports, while others have only mechanistic signals and no controlled combination trials.

⚠ Alkohol

Risiko: AVOID

Concurrent use of kava and alcohol is not recommended:

  • 1.Additive CNS effects: Drowsiness, slower reactions and impaired coordination may increase.
  • 2.Liver risk not quantified: A combined liver risk has not been quantified reliably; the combination is avoided because of this uncertainty.
  • 3.Unpredictable intensity: Product, amount, drinking pattern and individual sensitivity make effects difficult to predict.

Do not use kava and alcohol together. The main practical reason is possible additive impairment of attention, reaction and coordination; the size of any additional liver risk is not reliably established.

⚠ Benzodiazepiner & sovemidler

Risiko: PROFESSIONAL REVIEW

Do not combine benzodiazepines or Z-drugs with kava without medical review:

  • •Additive sedation: Drowsiness and psychomotor impairment may increase.
  • •CNS depression: Clinically relevant potentiation is possible; controlled combination trials are lacking.
  • •Interpret CYP findings: CYP3A4 inhibition was observed in vitro but not consistently confirmed in small human studies.

Tilfellerapport: Almeida & Grimsley (1996) described a semicomatose state in a 54-year-old man after reported kava and alprazolam use. A single case report is a warning signal but does not establish mechanism or frequency.

⚠ Antipsykotika

Risiko: PROFESSIONAL REVIEW

Individual medical review is appropriate before kava use with antipsychotics:

  • •Sedation: Additive drowsiness or psychomotor impairment is possible.
  • •Case reports: Individual reports describe movement disorders; frequency and causality are unclear.
  • •CYP findings: Laboratory inhibition does not reliably predict the level of a specific medicine.

⚠ Antikoagulantia (blodfortynnere)

Risiko: PROFESSIONAL REVIEW

Warfarin, phenprocoumon and other anticoagulants require professional review because of their narrow therapeutic window:

  • •Mechanistic signal: CYP2C9 inhibition was observed in vitro; a clinical kava-warfarin interaction has not been established in controlled studies.
  • •Monitor INR: Changes in co-used products should be coordinated with the treating clinician.
  • •Bleeding risk: The baseline risk of anticoagulation makes self-testing inappropriate.

Use kava with anticoagulation only after individual medical review.

Kombinasjoner med moderat risiko

Følgende kombinasjoner krever forsiktighet og bør kun gjøres etter konsultasjon med lege. En dosejustering kan være nødvendig.

Antidepressiva

Risiko: PROFESSIONAL REVIEW

SSRI (fluoksetin, sertralin, paroksetin osv.):
  • • Pharmacokinetic interactions may occur depending on the product but are not clinically established as a class
  • • Serotonin syndrome from kava is not established as a typical clinical effect
  • • Additive drowsiness or dizziness are possible
SNRI (venlafaksin, duloksetin):
  • • Direct clinical combination data are limited
  • • Review co-medication individually rather than inferring from in-vitro CYP data
MAO-hemmere:
  • • MAO-B effects of individual kavalactones have been studied preclinically
  • • Pawa et al. (2026) found MAO-A inhibition by flavokawain A in an in-vitro enzyme assay; humans and combination with MAO inhibitors were not studied
  • • Do not self-combine with MAO inhibitors because medicine interactions can be serious
  • • Obtain medical review before use

Antikonvulsiva (antiepileptika)

Risiko: PROFESSIONAL REVIEW

Fenytoin, karbamazepin, valproat og andre antikonvulsiva:

  • •Pharmacokinetics: Altered levels are possible but cannot be predicted reliably for individual combinations.
  • •CNS effects: Additive drowsiness or coordination problems are possible.
  • •Seizure control: Changes in co-used products belong under professional supervision.

Ved epilepsi bør Kava kun brukes under medisinsk tilsyn.

Parkinson-medisiner

Risiko: PROFESSIONAL REVIEW

Levodopa og dopaminagonister:

  • •Mechanism unclear: Blanket clinical dopamine antagonism by kava has not been established.
  • •Case reports: Individual reports describe worsening Parkinson symptoms; medical review is therefore needed.

With Parkinson's disease or related medication, use kava only after medical review.

Hepatotoksiske legemidler

Risiko: MODERAT

Legemidler med kjent hepatotoksisk potensial:

  • •Paracetamol/acetaminophen: Spesielt problematisk ved høyere doser
  • •Statiner: Atorvastatin, simvastatin osv. (CYP3A4-substrater)
  • •Metotreksat: Immunosuppressiv med hepatotoksisitet
  • •Isoniazid: Tuberkulose-medisiner

Additional liver risk is plausible but not quantified for every combination. Potentially hepatotoxic medication requires individual medical review.

Oversiktstabell over interaksjoner

StoffklasseEksemplerRisikoMekanisme
AlkoholEthanolAVOIDPossible additive sedation and impaired coordination; liver risk not quantified
BenzodiazepinerDiazepam, lorazepam, alprazolamPROFESSIONAL REVIEWPossible additive CNS depression; one case report, no controlled combination trials
AntipsykotikaHaloperidol, olanzapin, klozapinPROFESSIONAL REVIEWSedation or interactions possible; direct clinical data limited
AntikoagulantiaWarfarin, fenprokumonPROFESSIONAL REVIEWNo controlled kava interaction established; narrow therapeutic window
SSRIFluoksetin, sertralin, paroksetinPROFESSIONAL REVIEWPossible sedation or pharmacokinetics; no established kava serotonin syndrome
AntikonvulsivaFenytoin, karbamazepinPROFESSIONAL REVIEWPossible additive CNS effects and unpredictable pharmacokinetics
Parkinson-medisinerLevodopa, dopaminagonisterPROFESSIONAL REVIEWCase reports of symptom worsening; no blanket dopamine antagonism established
StatinerAtorvastatin, simvastatinPROFESSIONAL REVIEWDirect clinical interaction data are lacking; review liver and medication context
OpioiderKodein, tramadol, morfinAVOID / REVIEWPossible additive CNS depression
KoffeinKaffe, energidrikkerCAUTIONHuman CYP1A2 findings are small and inconsistent

Praktiske anbefalinger

Sjekkliste før Kava-konsum

  • 1.
    Sjekk medisinlisten

    Kontroller alle nåværende legemidler for interaksjoner

  • 2.
    Konsulter lege

    Ved regelmessig legemiddelbruk, søk medisinsk råd før Kava-konsum

  • 3.
    Unngå alkohol

    Do not use kava and alcohol together. The main practical reason is possible additive impairment of attention, reaction and coordination; the size of any additional liver risk is not reliably established.

  • 4.
    Dosere lavt

    Do not experiment with a self-selected lower kava dose while taking medicines; obtain professional review of the combination.

  • 5.
    Observer symptomer

    Vær oppmerksom på uvanlig tretthet, svimmelhet eller andre symptomer

Fortsett i kapittelet Sikkerhet

Basert på studier av

Christopher McCurdy

University of Florida College of Pharmacy

Se profil →

Med bidrag fra

Dette wiki er en kuratert ressurs som syntetiserer forskning fra fagfellevurderte studier og ekspertforskere. Det er ikke skrevet av forskerne oppført ovenfor, men snarere basert på deres publiserte arbeid.

Vitenskapelige Kilder

Informasjonen på denne siden er basert på følgende vitenskapelige studier og publikasjoner:

Cytochrome P450 2E1 (CYP2E1) Is the Principal Enzyme Responsible for Urethane Metabolism

Hoffler U., El-Masri H.A., Ghanayem B.I. (2003) – Journal of Pharmacology and Experimental Therapeutics

Se studie

Kava: From Ethnology to Pharmacology

Yadhu N. Singh (Editor) (2004) – CRC Press

Se studie
Last updated: 18. mars 2026•New study added