Medication interaction hub

What Supplements Interact with Fosphenytoin Sodium?

Fosphenytoin Sodium brand name: Sesquient. Every interaction below applies to the brands too.

212 Interactions 14 Major 179 Moderate 19 Minor
Curated & coded by · Clinical Pharmacist · Updated October 6, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Fosphenytoin Sodium? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Fosphenytoin Sodium against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

Fosphenytoin sodium (Sesquient) converts to phenytoin in the body, and phenytoin is unforgiving about blood levels. A little too low invites seizures, a little too high brings toxicity. That makes the 212 supplements and herbs on this page a list to respect rather than skim. The largest cluster, 78 ingredients including kava and alcoholic drinks, deepens the drug's sedation, in the worst cases to the point of dangerous drowsiness. St. John's wort stands apart because it can drive phenytoin levels down far enough to let seizures return.

Fourteen entries carry a major rating, and those deserve your attention ahead of the 179 moderate and 19 minor ones. Beyond sedation, 38 ingredients can stress the liver, 13 can disturb heart rhythm, and dozens more act on the liver enzymes that clear phenytoin, nudging its level up or down. Even folic acid at 1 mg or more can lower phenytoin levels in some people.

— , Clinical Pharmacist · July 18, 2026

Major 14 Moderate 179 Minor 19 No known interaction 1,240

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Most Viewed Ingredient Interactions

Fosphenytoin Sodium: Top Interactions at a Glance

The Fosphenytoin Sodium supplement & herbal interactions people checked most in the last 24 hours, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 212 interacting ingredients — plus 1,240 more checked with no known interaction. See the complete ranked list.

Start here

The Most-Checked Fosphenytoin Sodium Combinations Today

The Fosphenytoin Sodium + supplement pages people viewed most in the last 24 hours (resets at midnight). Open any card for the full report.

Moderate Likelihood Possible Hops + Fosphenytoin Sodiumi

Theoretically, concomitant use of hops with sedative drugs might cause additive sedation.

Read the full interaction Moderate Likelihood Possible European Barberry + Fosphenytoin Sodiumi

Theoretically, concomitant use with drugs that have sedative properties may cause additive effects.

Read the full interaction Moderate Likelihood Possible Vitamin A + Fosphenytoin Sodiumi

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.

Read the full interaction Moderate Likelihood Possible Cannabis + Fosphenytoin Sodiumi

Theoretically, cannabis might have additive effects if used with other CNS depressants.

Read the full interaction Moderate Likelihood Possible Vitamin B6 + Fosphenytoin Sodiumi

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.

Read the full interaction Moderate Likelihood Possible Baikal Skullcap + Fosphenytoin Sodiumi

Theoretically, Baikal skullcap might increase levels of drugs metabolized by CYP2C19 enzymes.

Read the full interaction
The complete list

Every Supplement Checked Against Fosphenytoin Sodium

All 1,452 ingredients in our database, ranked by severity — 212 with a Fosphenytoin Sodium interaction on file and 1,240 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Fosphenytoin Sodium?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Hops with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of hops with sedative drugs might cause additive sedation.

Full Hops + Fosphenytoin Sodium answer

Can you take European Barberry with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use with drugs that have sedative properties may cause additive effects.

Full European Barberry + Fosphenytoin Sodium answer

Can you take Vitamin A with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disea...

Full Vitamin A + Fosphenytoin Sodium answer

Can you take Cannabis with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, cannabis might have additive effects if used with other CNS depressants.

Full Cannabis + Fosphenytoin Sodium answer

Can you take Vitamin B6 with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.

Full Vitamin B6 + Fosphenytoin Sodium answer

Can you take Bacopa with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, bacopa might increase the levels and adverse effects of CYP2C19 substrates.

Full Bacopa + Fosphenytoin Sodium answer

Can you take Baikal Skullcap with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Baikal skullcap might increase levels of drugs metabolized by CYP2C19 enzymes.

Full Baikal Skullcap + Fosphenytoin Sodium answer

Can you take Bay Leaf with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking bay leaf in large amounts may enhance the therapeutic and adverse effects of sedatives.

Full Bay Leaf + Fosphenytoin Sodium answer

Can you take Berberine with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, berberine might increase the sedative effects of CNS depressants.

Full Berberine + Fosphenytoin Sodium answer

Can you take Bitter Almond with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, bitter almond oil may have additive effects with other CNS depressants.

Full Bitter Almond + Fosphenytoin Sodium answer

Can you take Bitter Orange with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the...

Full Bitter Orange + Fosphenytoin Sodium answer

Can you take Black Cohosh with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking black cohosh with hepatotoxic drugs may increase the risk of liver damage.

Full Black Cohosh + Fosphenytoin Sodium answer

Can you take Black Pepper with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Black pepper might increase blood levels of phenytoin.

Full Black Pepper + Fosphenytoin Sodium answer

Can you take Black Seed with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use with drugs that have sedative properties may cause additive effects.

Full Black Seed + Fosphenytoin Sodium answer

Can you take Black Tea with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, black tea might reduce the effects of phenytoin and increase the risk for convulsions.

Full Black Tea + Fosphenytoin Sodium answer

Can you take Boldo with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Full Boldo + Fosphenytoin Sodium answer

Can you take Boneset with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Boneset belongs to the genus Eupatorium, and many species of this genus contain hepatotoxic pyrrolizidine alkaloids (PAs).

Full Boneset + Fosphenytoin Sodium answer

Can you take Borage with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking borage with drugs that induce CYP3A4 might increase levels of pyrrolizidine alkaloid (PA) toxic metabolites.

Full Borage + Fosphenytoin Sodium answer

Can you take Boswellia Serrata with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Boswellia serrata might increase the levels of CYP2C19 substrates.

Full Boswellia Serrata + Fosphenytoin Sodium answer

Can you take Buchu with Fosphenytoin Sodium?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Buchu contains pulegone, a known hepatotoxin.

Full Buchu + Fosphenytoin Sodium answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Fosphenytoin Sodium is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Fosphenytoin Sodium, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Fosphenytoin Sodium sits in 12 interaction categories. Open any one to see what the group means:

Cns Depressants 78 ingredients

Central-nervous-system depressants. Sedating supplements can intensify drowsiness and slowed reactions when combined.

78 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 2C9 (Cyp2C9) Substrates 64 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

64 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Hepatotoxic Drugs 38 ingredients

Medications with known liver considerations. Supplements that can stress the liver add to the load.

38 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 2C19 (Cyp2C19) Substrates 33 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

33 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Phenytoin (Dilantin) 23 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

23 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 3A4 (Cyp3A4) Inducers 19 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

19 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Anticonvulsants 15 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

15 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Qt Interval-Prolonging Drugs 13 ingredients

Medications that can affect the heart's electrical rhythm (the QT interval). Supplements with similar effects can add to that risk.

13 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 2C9 (Cyp2C9) Inducers 3 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

3 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 2C19 (Cyp2C19) Inducers 2 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

2 of the supplement ingredients on this page reach Fosphenytoin Sodium through this category.

Cytochrome P450 1A2 (Cyp1A2) Inducers 1 ingredient

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

1 of the supplement ingredient on this page reaches Fosphenytoin Sodium through this category.

Phenytoin (Dilantin) 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Fosphenytoin Sodium through this category.

Related: does Fosphenytoin Sodium deplete any nutrients?

Fosphenytoin Sodium has 1 reported nutrient association in the research literature — see the Fosphenytoin Sodium nutrient depletion report.

Check a real product

Take a Supplement Product? Check the Whole Bottle Against Fosphenytoin Sodium

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Fosphenytoin Sodium.

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Pharmacist Counseling Corner

Fosphenytoin Sodium & Supplements: Common Questions

What supplements interact with Fosphenytoin Sodium?
Our database currently documents 212 ingredients with a known Fosphenytoin Sodium interaction (14 major, 179 moderate, 19 minor). The practical move: scan the major group first, then look up the exact supplements you take rather than reading all 212. The highest-ranked right now: Beer, Siberian Cocklebur, St. John's Wort.
Which Fosphenytoin Sodium supplement interactions are the most serious?
The 14 major-rated combinations — led by Beer, Siberian Cocklebur, St. John's Wort, Wine and 1,4-butanediol — deserve real caution: these are the ones generally best avoided, or used only with your prescriber watching. If you take any of them today, don't panic and don't stop anything abruptly — call your pharmacist first. Jump to the ranked list.
Can I take vitamins or supplements while on Fosphenytoin Sodium?
Plenty of supplements coexist fine with Fosphenytoin Sodium; a shorter list does not. Rather than memorizing it, check the specific ingredients on your labels — the ranked list above covers every one we've checked, and multi-ingredient products can be checked label-by-label with our scanner. Try the label scanner or the interaction checker.
Do brands like Sesquient have the same supplement interactions as Fosphenytoin Sodium?
Yes — Sesquient all contain Fosphenytoin Sodium, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
Does Fosphenytoin Sodium deplete any vitamins or nutrients?
It might — Fosphenytoin Sodium has 1 reported nutrient-depletion association in the research literature, which is a different question from interactions: instead of a supplement changing the drug, the drug may lower a nutrient over time. See the Fosphenytoin Sodium nutrient depletion report for the specifics and what to discuss with your pharmacist.
What about Fosphenytoin Sodium and my other medications?
This page covers Fosphenytoin Sodium against supplements and herbal ingredients. Checking Fosphenytoin Sodium against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker.

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

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of October 6, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.