Drug & supplement interaction

Cannabis + Itraconazole

Itraconazole brand names: Sporanox, Sporanox Injection, Tolsura.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Itraconazole falls into 4 drug categories that Cannabis can interact with; the most serious is rated moderate. Theoretically, drugs that are CYP2C9 inhibitors might increase the adverse effects of cannabis.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cannabis and Itraconazole

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Cannabis interacts with whole categories of medication. Itraconazole falls into 4 of those categories, so it can interact with Cannabis in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C9 (CYP2C9) INHIBITORS

1 of 4

Why this applies to Itraconazole

Itraconazole falls under CYTOCHROME P450 2C9 (CYP2C9) INHIBITORS — the group Cannabis interacts with.

Theoretically, drugs that are CYP2C9 inhibitors might increase the adverse effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP2C9 enzymes.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: itraconazole can slow down one of the liver enzymes (CYP2C9) that helps break down THC, the active part of cannabis that gets you high. When that cleanup slows, THC can hang around longer and build up. So while you're taking itraconazole for your fungal infection, the same amount of cannabis might hit harder than usual, meaning more drowsiness, dizziness, a stronger high, a racing heart, or feeling out of it.

I'll be honest with you: this one is theoretical, based on how these things work on paper rather than strong real-world studies, so it may never cause you a noticeable problem. Still, it's worth a quick chat with your pharmacist or doctor, and go easy if you do use cannabis during treatment.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

2 of 4

Itraconazole also falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS.

Theoretically, CYP3A4 inhibitors might increase the levels and adverse effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP3A4 enzymes.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version: itraconazole is a strong blocker of an enzyme called CYP3A4, and your body uses that same enzyme to help break down THC, the part of cannabis that gets you high. When itraconazole slows that cleanup process, THC can hang around longer and build up, so the cannabis may hit harder or last longer than you expect. That could mean more drowsiness, dizziness, a stronger high, a racing heart, or feeling more out of it.

I want to be honest that this is a theoretical concern based on how these drugs work, not strong patient studies. It's not dangerous for most people, but if you use cannabis while taking itraconazole, go slow and let your pharmacist or doctor know so they can guide you safely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 4

Itraconazole also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, cannabis may increase the levels and adverse effects of CYP3A4 substrates.
In vitro research shows that cannabis can inhibit the activity of CYP3A4 enzymes, which might decrease the metabolism of CYP3A4 substrates. In vitro research also shows that cannabis extracts modestly inhibit the CYP3A4 metabolism of testosterone; extracts providing the specific cannabinoids CBD and cannabigerol (CBG) had stronger inhibitory effects than extracts containing THC and CBD.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea with itraconazole. Your liver uses an enzyme called CYP3A4 to help break it down, and lab studies suggest cannabis can slow that same enzyme. If your body clears itraconazole more slowly, levels could creep up, which may mean more of the usual side effects like nausea, stomach upset, headache, or dizziness. At higher levels there are also worries about liver strain and heart rhythm changes, so it's not something to brush off.

That said, this is based only on test-tube research, not real patients, so we honestly don't know how much it matters day to day. I wouldn't panic, but I also wouldn't combine them on your own. Please loop in your pharmacist or doctor before using cannabis with this antifungal.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pellinen, P., Honkakoski, P., Stenback, F., Niemitz, M., Alhava, E., Pelkonen, O., Lang, M. A., and Pasanen, M. Cocaine N-demethylation and the metabolism-related hepatotoxicity can be prevented by cytochrome P450 3A inhibitors. Eur.J Pharmacol 1-3-1994;2 PubMed
  2. Treyer A, Reinhardt JK, Eigenmann DE, Oufir M, Hamburger M. Phytochemical comparison of medicinal cannabis extracts and study of their CYP-mediated interactions with coumarinic oral anticoagulants. Med Cannabis Cannabinoids. 2023;6(1):21-31. PubMed
Moderate

P-GLYCOPROTEIN SUBSTRATES

4 of 4

Itraconazole also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, cannabis might alter levels of drugs that are substrates of P-glycoprotein (P-gp).
Most in vitro research suggests that constituents of cannabis, including cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), can inhibit P-gp and increase the accumulation of probe compounds by reducing P-gp mediated drug efflux. In vitro studies in kidney cell lines show that a 1-hour exposure to CBD and THC inhibits P-gp. Cannabis may also alter the expression of P-gp, although this effect appears to vary based on duration of exposure. Some in vitro research in lymphoblastoid leukemia cell lines indicates that a 1-hour exposure to cannabinoids does not affect P-gp expression, while a prolonged 72-hour exposure decreases P-gp expression. Other in vitro research in these cell lines shows that a 4-hour exposure to THC and CBD induces P-gp gene expression, while exposure for longer than 4 hours and up to 48 hours does not induce P-gp gene expression.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea: your body uses a kind of cellular bouncer called P-glycoprotein (P-gp) to pump certain drugs back out of cells and help move them along for removal. Itraconazole is partly handled by this pump. Lab and animal studies suggest cannabis compounds (THC and CBD) may slow that pump down. In theory, that could let a bit more itraconazole build up, which might mean stronger effects or more side effects like nausea, stomach upset, headache, or in rare cases liver strain.

That said, this comes only from test-tube and animal research, not real-world patient data, so it's quite uncertain. Itraconazole isn't a prodrug, so the direction would be more drug, not less. Before combining them, please check with your pharmacist or doctor, especially since cannabis can also affect itraconazole through other liver pathways.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zhu, H. J., Wang, J. S., Markowitz, J. S., Donovan, J. L., Gibson, B. B., Gefroh, H. A., and Devane, C. L. Characterization of P-glycoprotein inhibition by major cannabinoids from marijuana. J Pharmacol Exp.Ther. 2006;317(2):850-857. PubMed
  2. Holland, M. L., Panetta, J. A., Hoskins, J. M., Bebawy, M., Roufogalis, B. D., Allen, J. D., and Arnold, J. C. The effects of cannabinoids on P-glycoprotein transport and expression in multidrug resistant cells. Biochem.Pharmacol 4-14-2006;71(8):1146-115 PubMed
  3. Tournier N, Lucie Chevillard L, Megarbane B, et al. Interaction of drugs of abuse and maintenance treatments with human P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). Int J Neuropsychopharmacol. 2010;13(7):905-15. PubMed
  4. Arnold JC, Hone P, Holland ML, Allen JD. CB2 and TRPV1 receptors mediate cannabinoid actions on MDR1 expression in multidrug resistant cells. Pharmacol Rep. 2012;64(3):751-7. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Cannabis Also Interacts With Other Medications

Cannabis has 2 major, 1,108 moderate, 25 minor known drug interactions in our database — the Itraconazole one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 1,108 Minor 25 No known interaction 1,695 (incl. Itraconazole)
Taking anything else?

Check Another of Your Medications Against Cannabis

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

From our Q&A

Questions About Cannabis or Itraconazole

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cannabis or Itraconazole, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Itraconazole

This page covers Cannabis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Itraconazole page lists 182 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 136 moderate · 40 minor.

From our pharmacist’s overview on the Itraconazole page

“Serious fungal infections are what itraconazole (Sporanox, Tolsura) is for, and the drug travels through CYP3A4, the liver enzyme that also handles a large share of supplements. That overlap is why this list reaches 182 ingredients, and it earns genuine care; start with the six rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Itraconazole interaction page

One more smart check

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

We hold 21 real supplement products containing Cannabis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cannabis. Your product may carry other ingredients that interact with Itraconazole too, on top of Cannabis — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cannabis and Itraconazole 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 Cannabis
Top 25%

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

29 days ago today
Medication Itraconazole
Steady interest

#1,779 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.

Supplement

About Cannabis

What is Cannabis?

Cannabis
  • Chronic pain
  • Nausea and vomiting from chemotherapy
  • Muscle spasticity (e.g., multiple sclerosis)
  • Anxiety and stress
  • Sleep problems
  • Appetite stimulation

Cannabis contains many active compounds, mainly THC (which causes a 'high') and CBD (which does not). Some uses, such as chemotherapy-related nausea, certain seizure disorders, and muscle spasticity, have meaningful evidence, while many other popular uses are not well proven. It can cause real side effects and impairment, so talk to your doctor or pharmacist and follow your local laws before using it.

Read the full Cannabis monograph & all interactions
Medication

About Itraconazole

What Is Itraconazole Used For?

Brand names: Sporanox, Sporanox Injection, Tolsura

Itraconazole capsules (including Sporanox capsules and generic itraconazole capsules) treat serious fungal infections — blastomycosis, histoplasmosis, and aspergillosis — in both people with normal immune systems and those who are immunocompromised. Capsule forms are also approved for nail fungus (onychomycosis) caused by dermatophytes in non-immunocompromised patients. Tolsura (a gelatin-coated capsule formulation) treats blastomycosis, histoplasmosis, and aspergillosis in adults, but is not approved for nail fungus and is not interchangeable with other itraconazole products.

Itraconazole oral solution is specifically approved for oropharyngeal candidiasis (thrush — a fungal infection of the mouth) and esophageal candidiasis (a fungal infection of the food pipe). Only the oral solution has been shown to work for these mouth and throat infections; capsules cannot be substituted for this use.

See full Itraconazole drug information
Keep checking

Other Drugs & Cannabis

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

2Major
1,108Moderate
25Minor
1,694No known interaction
2 Major 1,108 Moderate 25 Minor 1,694 No interaction
Major

2 interactions

Moderate

1,108 interactions

Showing 60 of 1,108 moderate interactions — see all 1,108 on the Cannabis page.

Minor

25 interactions

No interaction 1,694 drugs checked — show the list

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

Showing the 60 most looked-up of 1,694 medications checked with no known interaction — see the full Cannabis list.

See the full Cannabis interactions page
See every supplement checked against Itraconazole, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

Parts of this content are provided by the Therapeutic Research Center, LLC.

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.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Cannabis monograph › Uses, safety, and every drug interaction in one place Itraconazole supplement interactions › Every supplement checked against Itraconazole, ranked by severity Itraconazole drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cannabis and Itraconazole Together: Common Questions

Can you take Cannabis with Itraconazole?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 4 interactions listed for Cannabis and Itraconazole?
Itraconazole belongs to more than one drug category, and Cannabis interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Cannabis and Itraconazole interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Itraconazole and Cannabis?

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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.