Drug Interaction Report

Ketoconazole Topical and Temsirolimus: Interaction Details

A pharmacist-reviewed analysis of the Ketoconazole Topical and Temsirolimus 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

Ketoconazole Topical

Extina® Foam Ketozole® Cream Kuric Nizoral AD® Shampoo Nizoral® Cream Nizoral® Shampoo Xolegel®
+

Temsirolimus

Torisel Torisel®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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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 546 documented Ketoconazole Topical interactions, 380 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
delayed
Evidence
probable
Severity
Major

What happens

Increased exposure and maximum concentration of sirolimus, the active metabolite of temsirolimus

Interaction Deep Dive

Avoid coadministration of ketoconazole and temsirolimus, as it has resulted in substantially increased exposure and maximum concentration of sirolimus (active metabolite of temsirolimus). If concurrent use of temsirolimus with a strong CYP3A4 inhibitor is clinically warranted, the temsirolimus dose may be decreased to 12.5 mg/week2. Upon discontinuation of the strong inhibitor, a washout period of approximately 1 week should be allowed before adjusting the temsirolimus dose back to its original dose used prior to initiation of the inhibitor 21.

Why it happens (mechanism)

Inhibition of CYP3A4-mediated metabolism of sirolimus (active metabolite of temsirolimus)

Literature reports

1 report — tap to read

a) Coadministration of ketoconazole, a potent CYP3A4 inhibitor, and temsirolimus increased the Cmax and AUC of sirolimus (active metabolite of temsirolimus) by 2.2-fold and 3.1-fold, respectively, compared to treatment with temsirolimus alone. The Cmax and AUC of temsirolimus were not significantly affected 2.

Common questions

Can I take Ketoconazole Topical and Temsirolimus together?

Increased exposure and maximum concentration of sirolimus, the active metabolite of temsirolimus Always confirm with your pharmacist or prescriber before making any change.

How serious is the Ketoconazole Topical and Temsirolimus interaction?

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

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Ketoconazole Topical or Temsirolimus 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 (2)

  1. Product Information: Ketoconazole oral tablet, ketoconazole oral tablet. Taro Pharmaceuticals U.S.A. Inc. (per DailyMed), Hawthorne, NY, 2024. DailyMed
  2. Product Information: TORISEL(R) Kit IV injection, temsirolimus IV injection. Wyeth Pharmaceuticals Inc (per FDA), Philadelphia, PA, 2011. DailyMed
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Ketoconazole Topical

Keep reading about Ketoconazole Topical

All Ketoconazole Topical interactions (546) Ketoconazole Topical drug information
Also serious with: Colchicine Conivaptan Crizotinib Dabrafenib
Temsirolimus

Keep reading about Temsirolimus

All Temsirolimus interactions (20) Temsirolimus drug information
Also serious with: Lisinopril Asciminib Perindopril Octreotide
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:

Temsirolimus + Asarabacca Grapefruit Siberian Cocklebur St. John's Wort Acacia Rigidula Active Hexose Correlated Compound (ahcc) Adrafinil African Wild Potato + 161 more

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

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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.