Drug & supplement interaction

African Wild Potato + Phenytoin

Phenytoin brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, and others.

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

Phenytoin falls into 2 drug categories that African Wild Potato can interact with; the most serious is rated moderate. In vitro research shows that African wild potato extract inhibits cytochrome P450 2C9 (CYP2C9).

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

African Wild Potato and Phenytoin

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

African Wild Potato interacts with whole categories of medication. Phenytoin falls into 2 of those categories, so it can interact with African Wild Potato in 2 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) SUBSTRATES

1 of 2

Why this applies to Phenytoin

Phenytoin falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group African Wild Potato interacts with.

In vitro research shows that African wild potato extract inhibits cytochrome P450 2C9 (CYP2C9). However, this effect has yet to be reported in humans. Until more is known, use with caution. Theoretically, concomitant use of African wild potato with CYP2C9 substrates might increase the risk for adverse effects from these substrates. Some of these drugs include nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac (Cataflam, Voltaren), ibuprofen (Motrin), meloxicam (Mobic), and piroxicam (Feldene); celecoxib (Celebrex); amitriptyline (Elavil); warfarin (Coumadin); glipizide (Glucotrol); losartan (Cozaar); and others.
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 gist for phenytoin (Dilantin). Your body relies on a liver enzyme called CYP2C9 to break this medicine down. In test-tube studies, African Wild Potato appears to block that same enzyme. If that also happens in people, your body would clear phenytoin more slowly, so the level could creep up.

Phenytoin is a tricky drug because the safe window is narrow. Even a small rise can bring on side effects like dizziness, slurred speech, unsteady walking, double vision, or drowsiness. The catch is that this is only laboratory evidence so far, never confirmed in humans, so I don't want to alarm you. Still, because phenytoin is so dose-sensitive, please check with your pharmacist or doctor before combining the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fasinu PS, Gutmann H, Schiller H, Bouic PJ, Rosenkranz B. The potential of Hypoxis hemerocallidea for herb-drug interaction. Pharm Biol. 2013 Dec;51(12):1499-507.
Moderate

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

2 of 2

Phenytoin also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.

In vitro research shows that African wild potato extract might inhibit cytochrome P450 2C8 (CYP2C8). However, this effect has yet to be reported in humans. Until more is known, use with caution. Theoretically, concomitant use of African wild potato with CYP2C8 substrates might increase the risk for adverse effects from these substrates. Some drugs metabolized by CYP2C8 include amiodarone (Cordarone), paclitaxel (Taxol); nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac (Cataflam, Voltaren) and ibuprofen (Motrin); rosiglitazone (Avandia); and others.
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 situation with African Wild Potato and Dilantin (phenytoin). In test tube studies, this plant appears to slow down a liver enzyme called CYP2C8, one of the routes your body uses to clear phenytoin. If that enzyme is blocked, phenytoin could build up to higher levels than expected. Since phenytoin is a narrow therapeutic index drug, meaning the gap between a helpful dose and a toxic one is small, even modest changes can matter. Too much can cause dizziness, slurred speech, unsteady walking, drowsiness, or jerky eye movements.

I want to be honest though: this is only laboratory evidence and hasn't been confirmed in real people, so it's theoretical for now. Still, please loop in your pharmacist or doctor before combining them, especially since phenytoin levels are often monitored with blood tests.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fasinu PS, Gutmann H, Schiller H, Bouic PJ, Rosenkranz B. The potential of Hypoxis hemerocallidea for herb-drug interaction. Pharm Biol. 2013 Dec;51(12):1499-507.

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

African Wild Potato Also Interacts With Other Medications

African Wild Potato has 1,004 moderate known drug interactions in our database — the Phenytoin one above is among them. If you take anything else, check it against the full list below.

Moderate 1,004 No known interaction 1,826 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against African Wild Potato

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

From our Q&A

Questions About African Wild Potato or Phenytoin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers African Wild Potato or Phenytoin, 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 Phenytoin

This page covers African Wild Potato only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenytoin page lists 224 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: 9 major · 187 moderate · 28 minor.

From our pharmacist’s overview on the Phenytoin page

“Phenytoin (Dilantin) is a seizure medicine with a narrow therapeutic index, meaning small changes in its blood level can bring seizures back or tip over into toxicity, so I treat its supplement list with real seriousness. The biggest group, 78 ingredients, piles on sedation, and alcohol, kava, and GHB all rate major for exactly that re…”

Reviewed by 2 · Jul 18, 2026

Open the Phenytoin interaction page

One more smart check

Taking African Wild Potato as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1 real supplement products containing African Wild Potato, each one broken down to its full ingredient list — and combination products often carry several ingredients besides African Wild Potato. Your product may carry other ingredients that interact with Phenytoin too, on top of African Wild Potato — 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 African Wild Potato and Phenytoin 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 African Wild Potato
Top half

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

29 days ago today
Medication Phenytoin
Top 25%

#364 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 African Wild Potato

What is African Wild Potato?

  • Immune support
  • Prostate and urinary symptoms
  • Inflammation
  • General tonic/wellness
  • Skin conditions

African Wild Potato (Hypoxis hemerocallidea) is a southern African plant traditionally used as a tonic and for immune, prostate, and inflammatory complaints. Human evidence for these uses is very limited, and safety—especially during pregnancy, breastfeeding, or with serious illness—is not well established. Talk to a pharmacist or doctor before using it.

Read the full African Wild Potato monograph & all interactions
Medication

About Phenytoin

What Is Phenytoin Used For?

Brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, Dilantin injection

Phenytoin is used to treat and prevent seizures. The specific types covered depend on the formulation. Oral extended-release capsules (including Phenytek), chewable tablets (including Dilantin Infatabs and Phenytoin Infatabs), and oral suspension (including Dilantin-125) are used for tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures; most oral forms also cover prevention and treatment of seizures occurring during or after neurosurgery. Chewable tablets and some capsule formulations also cover complex partial seizures.

Parenteral (injectable) phenytoin sodium is used for generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and for prevention and treatment of seizures during neurosurgery. The IV form can also substitute short-term for oral phenytoin when a patient cannot take it by mouth.

See full Phenytoin drug information
Keep checking

Other Drugs & African Wild Potato

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

0Major
1,004Moderate
0Minor
1,825No known interaction
1,004 Moderate 1,825 No interaction
Moderate

1,004 interactions

Showing 60 of 1,004 moderate interactions — see all 1,004 on the African Wild Potato page.

No interaction 1,825 drugs checked — show the list

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

Showing the 60 most looked-up of 1,825 medications checked with no known interaction — see the full African Wild Potato list.

See the full African Wild Potato interactions page
See every supplement checked against Phenytoin, 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
African Wild Potato monograph › Uses, safety, and every drug interaction in one place Phenytoin supplement interactions › Every supplement checked against Phenytoin, ranked by severity Phenytoin 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 African Wild Potato and Phenytoin Together: Common Questions

Can you take African Wild Potato with Phenytoin?
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 2 interactions listed for African Wild Potato and Phenytoin?
Phenytoin belongs to more than one drug category, and African Wild Potato 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 African Wild Potato and Phenytoin 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 Phenytoin and African Wild Potato?

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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.