Drug & supplement interaction

Shiitake Mushroom + Primidone

Primidone brand name: Mysoline.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Shiitake Mushroom and Primidone 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

Shiitake Mushroom and Primidone

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 Primidone and Shiitake Mushroom 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.

Shiitake Mushroom safety at a glance

Shiitake Mushroom overall Use caution Generally safe as a food, but concentrated supplements and raw mushrooms can cause reactions in some people.
Pregnancy Use caution Eating shiitake as food is likely fine, but concentrated supplements should be avoided due to lack of safety data.
Breastfeeding Use caution Food amounts are likely fine, but there is not enough data on supplement doses, so caution is advised.

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

Still wondering about combining Primidone and Shiitake Mushroom? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Primidone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Primidone is filed under 7 classifications — including cytochrome p450 2c9 (cyp2c9) inducers, anticonvulsants, cytochrome p450 1a2 (cyp1a2) inducers. Shiitake Mushroom has documented interactions with 2 drug classes — the most serious being cytochrome p450 2d6 (cyp2d6) substrates (moderate) and immunosuppressants (moderate) — and none of Primidone’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

Shiitake Mushroom Does Interact With Other Medications

Shiitake Mushroom has 312 moderate known drug interactions in our database — Primidone isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Shiitake Mushroom

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

What to actually watch for

No Interaction Found — But Data Suggests Shiitake Mushroom and Primidone 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. One of them is worth acting on rather than waiting out — marked below.

  • A low white blood cell count Worth acting on Additional detail

    Shiitake Mushroom

    “Ingestion of shiitake mushroom powder 4 grams daily for 10 weeks caused eosinophilia in 5 of 10 healthy humans. Eosinophilia, and leukocytosis or leukopenia have been reported with shiitake dermatitis.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    4 sources cited
    1. 1149. Levy AM, Kita H, Phillips SF, et al. Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 1998;101:613-20. PubMed
    2. 94254. Mendonça CN, Silva PM, Avelleira JC, Nishimori FS, Cassia Fde F. Shiitake dermatitis. An Bras Dermatol. 2015 Mar-Apr;90(2):276-8.
    3. 94256. Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017 Jun;56(6):610-616. PubMed
    4. 94257. Poppe LM, Anders D, Kneitz H, Bröcker EB, Benoit S. Flagellate dermatitis caused by shiitake mushrooms. An Bras Dermatol. 2012 May-Jun;87(3):463-5. PubMed

    Primidone

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

  • Tiredness reported in 6.3% of FDA reports for Primidone Additional detail

    Shiitake Mushroom

    “In patients experiencing shiitake dermatitis, other symptoms may include prickling in the hands. Malaise has also been reported following oral intake or contact.

    Orally, the shiitake mushroom extract AHCC has been reported to cause mild and transient headache.”

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

    4 sources cited
    1. 94256. Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017 Jun;56(6):610-616. PubMed
    2. 1151. Matsui S, Nakazawa T, Umegae Y, Mori M. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31:1204-6.
    3. 94240. Baran W, Batycka-Baran A, Maj J, Szepietowski JC. Shiitake dermatitis - now also in Poland. Acta Derm Venereol. 2015 Jan;95(1):102-3. PubMed
    4. 30365. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed

    “Orally, shiitake mushrooms can cause shiitake dermatitis, a skin eruption that resembles whiplash marks, usually found on the trunk and limbs. This dermatitis is thought to be a toxic response to lentinan or other compounds found normally in uncooked or inadequately cooked shiitake mushroom. The rash can be made worse by scratching.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 1148. Hanada K, Hashimoto I. Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatol 1998;197:255-7. PubMed
    2. 1152. Nakamura T. Shiitake (Lentinus edodes) dermatitis. Contact Dermatitis 1992;27:65-70.
    3. 74782. Lippert, U., Martin, V., Schwertfeger, C., Junghans, V., Ellinghaus, B., and Fuchs, T. Shiitake dermatitis. Br.J Dermatol. 2003;148(1):178-179.
    4. 74806. Mak, R. K. and Wakelin, S. H. Shiitake dermatitis: the first case reported from a European country. Br J Dermatol 2006;154(4):800-801. PubMed
    5. 94236. Ade R, Sukut C, Wiser HJ, Shockman S, Buescher L. Shiitake dermatitis demonstrating Köebner phenomenon. Int J Dermatol. 2015;54(5):e179-81.
    6. 94237. Adler MJ, Larsen WG. Clinical variability of shiitake dermatitis. J Am Acad Dermatol. 2012 Oct;67(4):e140-1. PubMed

    Primidone

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

  • Nausea / Vomiting reported in 4.6% of FDA reports for Primidone Additional detail

    Shiitake Mushroom

    “Orally, shiitake mushrooms can cause abdominal discomfort, including bloating, nausea, pain, vomiting, and diarrhea. Gastrointestinal symptoms, such as diarrhea, problems swallowing, or mouth ulcers have been associated with shiitake dermatitis.”

    Shiitake Mushroom · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 1149. Levy AM, Kita H, Phillips SF, et al. Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 1998;101:613-20. PubMed
    2. 30365. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed
    3. 30375. Sumiyoshi, Y., Hashine, K., Kakehi, Y., Yoshimura, K., Satou, T., Kuruma, H., Namiki, S., and Shinohara, N. Dietary administration of mushroom mycelium extracts in patients with early stage prostate cancers managed expectantly: a phase II study. Jpn.J Cl PubMed
    4. 30419. Thaiudom, S., Piyaniran, W., and Chutaputthi, A. A study of the efficacy of Active Hexose Correlated Compound (AHCC) in the treatment of chronic Hepatitis C patients at Phramongkutklao Hospital. The Medical News (Thailand) 2010;325:13-16.
    5. 94241. Boels D, Landreau A, Bruneau C, et al. Shiitake dermatitis recorded by French Poison Control Centers - new case series with clinical observations. Clin Toxicol (Phila). 2014 Jul;52(6):625-8. PubMed
    6. 94256. Nguyen AH, Gonzaga MI, Lim VM, Adler MJ, Mitkov MV, Cappel MA. Clinical features of shiitake dermatitis: a systematic review. Int J Dermatol. 2017 Jun;56(6):610-616. PubMed

    Primidone

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

Reported for Shiitake Mushroom but not commonly for Primidone: sun sensitivity, stomach upset, mouth irritation or sores and shortness of breath.

Effects for Primidone come from the ADVERSE REACTIONS section of its FDA label; effects for Shiitake Mushroom come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 9,961 voluntary FDA FAERS reports for Primidone 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.

From our Q&A

Questions About Shiitake Mushroom or Primidone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Shiitake Mushroom or Primidone, 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 Primidone

This page covers Shiitake Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Primidone page lists 124 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 101 moderate · 16 minor.

Open the Primidone interaction page

One more smart check

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

We hold 1,613 real supplement products containing Shiitake Mushroom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Shiitake Mushroom. Even though Shiitake Mushroom itself has no known interaction with Primidone, 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 Shiitake Mushroom and Primidone 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 Shiitake Mushroom
Top 25%

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

29 days ago today
Medication Primidone
Steady interest

#2,136 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 Shiitake Mushroom reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Shiitake Mushroom and Primidone 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 Shiitake Mushroom

What is Shiitake Mushroom?

  • Immune support
  • General wellness and nutrition
  • Cholesterol and heart health
  • Adjunct in cancer care (lentinan, AHCC)
  • Antioxidant support

Shiitake is a popular edible mushroom that is nutritious and safe to eat as food for most people. Some of its extracts (like lentinan and AHCC) have been studied as immune support, mainly alongside cancer treatment, but evidence for most supplement uses is limited. Talk with your pharmacist or doctor before using concentrated shiitake supplements.

Lentinula edodes · Omphalotaceae · Fruiting body (mushroom cap and stem); mycelium extracts · Whole food (fresh or dried mushrooms), capsules, tablets, powders, liquid extracts, and standardized extracts such as lentinan and AHCC

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

Shiitake Mushroom: dosing

There is no official standardized dose for shiitake supplements, and products vary widely in strength and form. Some research used specialized extracts (like lentinan given by injection in a medical setting), which is very different from over-the-counter capsules.If you choose a shiitake supplement, follow the directions on the product label and do not exceed the recommended amount.

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

Read the full Shiitake Mushroom monograph & all interactions
Medication

About Primidone

What Is Primidone Used For?

Brand name: Mysoline

Primidone tablets — sold as Mysoline or under the generic name primidone — are used to control seizures in people with epilepsy. Both Mysoline and primidone tablets are approved for grand mal (generalized tonic-clonic), psychomotor, and focal (partial) epileptic seizures.

Primidone can be used alone or alongside other anti-seizure medicines. It may also help control grand mal seizures that haven't responded well to other anticonvulsant treatments.

Most-Reported Side Effects for Primidone

From FAERS, the FDA’s public side-effect reporting system (10,126 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fall 670 reports
Fatigue 645 reports
Tremor 585 reports
Diarrhea 499 reports
Dizziness 498 reports
See full Primidone drug information
Keep checking

Other Drugs & Shiitake Mushroom

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

0Major
312Moderate
0Minor
2,517No known interaction
Moderate

312 interactions

Showing 60 of 312 moderate interactions — see all 312 on the Shiitake Mushroom page.

No interaction 2,517 drugs checked — show the list
Evidence & sources

Shiitake Mushroom References

The 67 references that drive our Shiitake Mushroom 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. Hitosugi M, Kitamura O, Takatsu A, Yoshino Y. Autopsy case of duodenal obstruction from impacted mushroom. J Gastroenterol 1998;33:562-5. PubMed
  2. Hanada K, Hashimoto I. Flagellate mushroom (Shiitake) dermatitis and photosensitivity. Dermatol 1998;197:255-7. PubMed
  3. Levy AM, Kita H, Phillips SF, et al. Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms. J Allergy Clin Immunol 1998;101:613-20. PubMed
  4. Murakami M, Kawabe K, Hosoi Y, et al. Decreased pulmonary perfusion in hypersensitivity pneumonitis caused by Shiitake mushroom spores. J Intern Med 1997;241:85-8. PubMed
  5. Matsui S, Nakazawa T, Umegae Y, Mori M. Hypersensitivity pneumonitis induced by Shiitake mushroom spores. Intern Med 1992;31:1204-6.
  6. Nakamura T. Shiitake (Lentinus edodes) dermatitis. Contact Dermatitis 1992;27:65-70.
  7. Ueda A, Obama K, Aoyama K, et al. Allergic contact dermatitis in shiitake (Lentinus edodes (Berk) Sing) growers. Contact Dermatitis 1992;26:228-33.
  8. Burikhanov, R. B., Wakame, K., Igarashi, Y., Wang, S., and Matsuzaki, S. Suppressive effect of active hexose correlated compound (AHCC) on thymic apoptosis induced by dexamethasone in the rat. Endocr.Regul. 2000;34(4):181-188.
  9. Gao, Y., Zhang, D., Sun, B., Fujii, H., Kosuna, K., and Yin, Z. Active hexose correlated compound enhances tumor surveillance through regulating both innate and adaptive immune responses. Cancer Immunol.Immunother. 2006;55(10):1258-1266. PubMed
  10. Ritz, B. W., Nogusa, S., Ackerman, E. A., and Gardner, E. M. Supplementation with active hexose correlated compound increases the innate immune response of young mice to primary influenza infection. J Nutr. 2006;136(11):2868-2873. PubMed
  11. Aviles, H., O'Donnell, P., Sun, B., and Sonnenfeld, G. Active hexose correlated compound (AHCC) enhances resistance to infection in a mouse model of surgical wound infection. Surg.Infect.(Larchmt.) 2006;7(6):527-535. PubMed
  12. Spierings, E. L., Fujii, H., Sun, B., and Walshe, T. A Phase I study of the safety of the nutritional supplement, active hexose correlated compound, AHCC, in healthy volunteers. J Nutr Sci Vitaminol.(Tokyo) 2007;53(6):536-539. PubMed
  13. Aviles, H., O'Donnell, P., Orshal, J., Fujii, H., Sun, B., and Sonnenfeld, G. Active hexose correlated compound activates immune function to decrease bacterial load in a murine model of intramuscular infection. Am J Surg. 2008;195(4):537-545. PubMed
  14. Ritz, B. W. Supplementation with active hexose correlated compound increases survival following infectious challenge in mice. Nutr.Rev. 2008;66(9):526-531. PubMed
  15. Terakawa, N., Matsui, Y., Satoi, S., Yanagimoto, H., Takahashi, K., Yamamoto, T., Yamao, J., Takai, S., Kwon, A. H., and Kamiyama, Y. Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: a double-blind, placebo-controll

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 Shiitake Mushroom and Primidone Together: Common Questions

Is it safe to take Shiitake Mushroom with Primidone?
We do not list a known interaction between Shiitake Mushroom and Primidone. 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 Shiitake Mushroom and Primidone have any of the same side effects?
Yes — our sources link each of them separately to 4 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 Shiitake Mushroom and Primidone combination checked?
Interactions in our licensed database are recorded against drug classes. Primidone is filed under 7 classifications, and Shiitake Mushroom has documented interactions with 2 drug classes — none of Primidone'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 Shiitake Mushroom interact with any other medications?
Yes. Shiitake Mushroom has 312 documented drug interactions in our database — Primidone 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 Primidone interact with any supplements?
Yes. Primidone has documented interactions with 124 supplements in our database — Shiitake Mushroom is not one of them. The Primidone 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 Primidone and Shiitake Mushroom?

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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.