The short answer
Have goldenseal reviewed before taking it with erdafitinib. A human study found a modest effect on a CYP3A probe drug, but this does not establish how much goldenseal changes erdafitinib levels or whether it increases toxicity.
What this answer covers
Hydrastis canadensis preparations with oral erdafitinib. Human CYP3A probe effects do not establish exact cancer-drug exposure or toxicity.
- Supplement or preparation
- Hydrastis canadensis
- Medication ingredient
- erdafitinib
Check the exact treatment
This review concerns oral erdafitinib tablets used for selected FGFR3-altered advanced bladder or urinary-tract cancers. Blood phosphate helps guide the initial dose decision, and monitoring continues during treatment. Supplements should be part of that individualized plan.
What the goldenseal study actually measured
A clinical study found about a 1.43-fold increase in midazolam total exposure after a particular goldenseal preparation. Other probe drugs behaved differently. This is evidence that the tested product can affect drug handling, but it is not proof that it acts like a strong inhibitor or changes all medicines by the same amount.
The cancer-drug data involve different substances
A human erdafitinib study used fluconazole and itraconazole, not goldenseal. Those inhibitors produced different, modest exposure increases, and the single-dose healthy-volunteer experiment did not identify a safety concern. CYP2C9 as well as CYP3A4 contributes to erdafitinib metabolism.
Avoid making your own dose adjustment
Show the pharmacist the goldenseal product, amount and recent use. The cancer team can decide whether to avoid it and how to monitor treatment. No validated goldenseal spacing interval or automatic cancer-drug dose change was established; do not use another inhibitor’s dose instructions on your own.
Evidence and practical considerations
Absorption & effectiveness
A possible metabolic interaction warrants review, while the original exact-pair exposure/toxicity assertion remains insufficiently demonstrated.
- Exact scope
- Hydrastis canadensis preparations with oral erdafitinib. Human CYP3A probe effects do not establish exact cancer-drug exposure or toxicity. with RxNorm 2123125 IN erdafitinib. Current exact oral product: BALVERSA oral erdafitinib tablets. Salt/formulation named explicitly; no transfer to unrelated drugs or routes.
- Medication form and route
- Oral
What remains uncertain
- Exact combination unstudied in checked originals. Tested goldenseal produced weak CYP3A probe inhibition, not demonstrated equivalence to label-defined moderate/strong inhibitors; no exact toxicity outcome.
Factors that may matter: Exact oral formulation and supplement preparation; Drug exposure versus clinical outcomes; Dose, duration and other medicines; Individual monitoring plan.
Read the supporting source summaries
Source 1: Current original prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed the exact oral formulation.
Phosphate elevations and soft-tissue mineralization; avoid phosphate-altering agents before initial titration and phosphate-increasing products thereafter; CYP3A/2C9 precautions.
How this applies: RxNorm 2123125 IN erdafitinib. Current exact oral product: BALVERSA oral erdafitinib tablets. Salt/formulation named explicitly; no transfer to unrelated drugs or routes.
Exact current oral product source, not a clinical trial of every supplement. Formulation, dose, population and mechanism remain explicit.
Source 2: Original clinical research
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Healthy adults in a clinical probe-cocktail study.
Midazolam AUC increased 1.43-fold; effects differed across other probes, with little effect on rosuvastatin/furosemide and reduced metformin exposure.
How this applies: Exact reported preparation, population and endpoints; transfer to erdafitinib explicitly limited.
Original body read; weak CYP3A effect in this tested preparation, not proof of strong/moderate inhibition, exact target drug exposure or toxicity.
Source 3: Original clinical research
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Healthy adults randomized by CYP2C9 genotype.
Parent AUC increased 48% with fluconazole and 34% with itraconazole; mostly mild adverse events, no safety concern in this single-dose experiment.
How this applies: Exact reported preparation, population and endpoints; transfer to erdafitinib explicitly limited.
Abstract-only drug inhibitors, not goldenseal; different CYP pathways and potency. No extrapolated toxicity rate.
Source 4: Medication terminology
rxnav.nlm.nih.gov · Source check Sep 10, 2026
Population: Terminology.
erdafitinib is IN.
How this applies: Exact ingredient.
Not clinical evidence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Sources checked and article drafted. |
Article revision: 96f79ec2771179ea
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.