Venetoclax and Ketoconazole Topical: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ketoconazole Topical
Venetoclax
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.
What happens
Increased venetoclax exposure and an increased risk of venetoclax toxicities including the risk of tumor lysis syndrome
Interaction Deep Dive
Concomitant use of venetoclax with strong CYP3A inhibitors that are also P-gp inhibitors may increase venetoclax exposure and increase risk of venetoclax toxicities including the risk of tumor lysis syndrome. Concomitant use with strong CYP3A inhibitors is contraindicated at venetoclax initiation and during ramp-up phase when treating chronic lymphocytic leukemia (CLL) or small lymphocytic leukemia (SLL). For patients who have completed the CLL/SLL ramp-up phase, are on a steady venetoclax dosage, and require a concomitant strong CYP3A inhibitor, reduce venetoclax to 100 mg daily. For patients with acute myeloid leukemia, coadministration with a strong CYP3A inhibitor during initiation and ramp-up phase requires venetoclax dosage reduction to 10 mg on day 1, 20 mg on day 2, 50 mg on day 3, and after ramp-up phase, give 100 mg daily thereafter. If coadministration is required, reduce the venetoclax dosage by at least 50%. In all patients, 2 to 3 days after discontinuation of a concurrent CYP3A inhibitor that is also a P-gp inhibitor, resume the venetoclax dosage that was used prior to initiating the inhibitor1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of venetoclax; inhibition of P-gp-mediated efflux transport of venetoclax
Literature reports
4 reports — tap to read
a) In a pharmacokinetic study in 11 healthy subjects, the administration of venetoclax with a single dose of rifAMPin 600 mg (OATP1B1/1B3 and P-gp inhibitor) increased the venetoclax Cmax by 106% and the AUC by 78% 1.
b) Concomitant use of ketoconazole (a strong CYP3A, P-gp, and BCRP inhibitor) 400 mg once daily for 7 days increased venetoclax Cmax by 130% and AUC0-INF by 540% 1.
c) Concomitant use of ritonavir (a strong CYP3A, P-gp, and OATP1B1/B3 inhibitor) 50 mg once daily for 14 days increased venetoclax Cmax by 140% and AUC by 690% 1.
d) Concomitant use of posaconazole (a strong CYP3A and P-gp inhibitor) 300 mg with venetoclax 50 mg and 100 mg for 7 days resulted in 61% and 86% higher venetoclax Cmax, respectively 1.
Common questions
Can I take Venetoclax and Ketoconazole Topical together?
Increased venetoclax exposure and an increased risk of venetoclax toxicities including the risk of tumor lysis syndrome Always confirm with your pharmacist or prescriber before making any change.
How serious is the Venetoclax and Ketoconazole Topical 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Venetoclax or Ketoconazole Topical 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 (1)
- Product Information: VENCLEXTA(R) oral tablets, venetoclax oral tablets. AbbVie Inc (per FDA), North Chicago, IL, 2022. DailyMed
Keep reading about Ketoconazole Topical
Keep reading about Venetoclax
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