Drug Interaction Report

Irinotecan Injection and Mitotane: Interaction Details

A pharmacist-reviewed analysis of the Irinotecan Injection and Mitotane interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Mitotane

Lysodren
+

Irinotecan Injection

Camptosar Camptosar® Onivyde
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 96 documented Irinotecan Injection interactions, 73 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Reduced irinotecan exposure and reduced irinotecan active metabolite exposure

Interaction Deep Dive

Avoid coadministration of irinotecan or irinotecan liposome (a CYP3A4 substrate) with a strong CYP3A4 inducer unless there are no alternative therapies, as exposure of irinotecan or its active metabolite, SN-38 may be reduced. Use alternative nonenzyme-inducing therapy beginning at least 2 weeks prior to initiation of irinotecan therapy21.

Why it happens (mechanism)

Induction of CYP3A4-mediated metabolism of irinotecan

Literature reports

1 report — tap to read

a) In a systematic review of studies of pharmacokinetic interactions involving St John's Wort, concomitant use with irinotecan in 1 study (N=5) resulted in a decrease in irinotecan AUC of 42% with a St. John's Wort dosage of 300 mg 3 times daily (hyperforin dose not known) 3.

Common questions

Can I take Irinotecan Injection and Mitotane together?

Reduced irinotecan exposure and reduced irinotecan active metabolite exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Irinotecan Injection and Mitotane interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Irinotecan Injection or Mitotane need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (3)

  1. Product Information: CAMPTOSAR(R) intravenous injection, irinotecan intravenous injection. Pharmacia & Upjohn Co (per Manufacturer), New York, NY, 2014. DailyMed
  2. Product Information: ONIVYDE(R) intravenous injection, irinotecan liposome intravenous injection. Ipsen Biopharmaceuticals Inc (per FDA), Cambridge, MA, 2024. DailyMed
  3. Chrubasik-Hausmann S, Vlachojannis J, & McLachlan AJ: Understanding drug interactions with St John's wort (Hypericum perforatum L.): impact of hyperforin content. J Pharm Pharmacol 2019; 71(1):129-138.
Was this write-up helpful?
Mitotane

Keep reading about Mitotane

All Mitotane interactions (99)
Also serious with: Doravirine Lurasidone Fostemsavir Lenacapavir Oral
Irinotecan Injection

Keep reading about Irinotecan Injection

All Irinotecan Injection interactions (96) Irinotecan Injection drug information
Also serious with: Rubella Virus Vaccine, Live Smallpox Monkeypox Vaccine Typhoid Vaccine Varicella Virus Vaccine, Live
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Mitotane + Activated Charcoal Coffee Charcoal European Mandrake Glucomannan Guar Gum Gum Arabic Slippery Elm Tragacanth + 9 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.