Drug & supplement interaction

Andiroba + Fosphenytoin

Fosphenytoin brand name: Cerebyx.

Minor Interaction
Medically reviewed by · Updated February 2024
The bottom line Minor

Andiroba has a minor interaction with Fosphenytoin. Andiroba contains fatty acid amides that have shown potential anticonvulsant effects in animal studies.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Andiroba and Fosphenytoin

Here is the interaction we found between these two, with the evidence behind it.

Minor

Anticonvulsants

Why this applies to Fosphenytoin

Fosphenytoin falls under Anticonvulsants — the group Andiroba interacts with.

Andiroba contains fatty acid amides that have shown potential anticonvulsant effects in animal studies. These compounds are believed to act as agonists at gamma-aminobutyric acid (GABA)-A receptors, similar to some anticonvulsant medications. There is a theoretical possibility that combining andiroba with anticonvulsants that also act on GABA receptors could enhance their effects, potentially leading to increased side effects (source: https://pubmed.ncbi.nlm.nih.gov/32164340). However, it's important to note that this is based on theoretical considerations, and more studies are needed to understand the actual interaction between andiroba and anticonvulsants in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the short version: there's only a theoretical concern here, and it leans toward andiroba possibly adding to fosphenytoin's calming effects in the brain. Some lab and animal work suggests compounds in andiroba may nudge GABA receptors, the same kind of pathway some seizure medicines use. On paper, that could pile on to fosphenytoin and bump up its sedative-type side effects, things like drowsiness, dizziness, unsteadiness, or trouble with balance and coordination.

That said, this is far from proven in people, and the database rates it minor and unlikely. Andiroba is also usually used on the skin, which makes a real interaction even less likely. Fosphenytoin is a finicky drug to dose, so don't start any andiroba product without checking with your doctor or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction

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

Andiroba Also Interacts With Other Medications

Andiroba has 49 minor known drug interactions in our database — the Fosphenytoin one above is one of them. If you take anything else, check it against the full list below.

Minor 49 No known interaction 2,781 (incl. Fosphenytoin)
Taking anything else?

Check Another of Your Medications Against Andiroba

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

Everything else you take

See Every Supplement That Interacts With Fosphenytoin

This page covers Andiroba only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fosphenytoin page lists 205 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 14 major · 172 moderate · 19 minor.

From our pharmacist’s overview on the Fosphenytoin page

“St. John's wort is the entry I would flag first with fosphenytoin (Cerebyx).”

Reviewed by 2 · Jul 18, 2026

Open the Fosphenytoin interaction page

How much people look this up

Where Andiroba and Fosphenytoin 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 Andiroba
Steady interest

#1,231 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Fosphenytoin
Steady interest

#2,129 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 Andiroba

What is Andiroba?

Andiroba
  • Skin care and wound healing
  • Insect repellent
  • Muscle and joint aches
  • Anti-inflammatory skin conditions
  • Hair and scalp care

Andiroba is an oil pressed from the seeds of an Amazonian tree, used mainly on the skin for inflammation, minor wounds, aches, and as an insect repellent. Most evidence comes from laboratory and animal studies, so its benefits in people are not well proven. It is most often used topically; avoid internal use and use during pregnancy or breastfeeding because safety has not been established.

Read the full Andiroba monograph & all interactions
Medication

About Fosphenytoin Injection

What Is Fosphenytoin Injection Used For?

Brand name: Cerebyx

Fosphenytoin injection is used to treat generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and to prevent or treat seizures that occur during or after brain surgery. It is given by intravenous (IV) or intramuscular (IM) injection in a hospital or clinical setting.

It can also be used short-term as a substitute for oral phenytoin when a patient cannot take medicine by mouth. This use is temporary — as soon as oral phenytoin is possible again, it should replace the injection.

See full Fosphenytoin Injection drug information
Keep checking

Other Drugs & Andiroba

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

0Major
0Moderate
49Minor
2,780No known interaction
49 Minor 2,780 No interaction
Minor

49 interactions

No interaction 2,780 drugs checked — show the list

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

Showing the 60 most looked-up of 2,780 medications checked with no known interaction — see the full Andiroba list.

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

Can you take Andiroba with Fosphenytoin?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Andiroba and Fosphenytoin interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Fosphenytoin and Andiroba?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.