Eliglustat and Ketoconazole Topical: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Eliglustat
Ketoconazole Topical
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 eliglustat exposure and an increased risk of cardiac arrhythmias from prolongation of the PR, QTc and/or QRS cardiac intervals
Interaction Deep Dive
Concomitant use of eliglustat and ketoconazole (a strong CYP3A4 inhibitor) increased eliglustat AUC 4.4-fold to 6.2-fold, while concomitant use with both ketoconazole and PARoxetine (a strong CYP2D6 inhibitor) increased eliglustat AUC 9.8-fold to 24.2-fold. In patients with Gaucher disease type 1 (GD1) who are intermediate and poor CYP2D6 metabolizers, concomitant use of eliglustat and strong CYP3A4 inhibitors is contraindicated. And in patients with Gaucher disease GD1 who are extensive CYP2D6 metabolizers, reduce the eliglustat dosage to 84 mg once daily if used concomitantly with a strong CYP3A4 inhibitor1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of eliglustat
Literature reports
2 reports — tap to read
a) Coadministration with the strong CYP3A4 inhibitor, ketoconazole, led to a 4-fold increase in eliglustat Cmax and a 4.4-fold increase in eliglustat AUC in extensive CYP2D6 metabolizers with Gaucher disease type 1. Among intermediate metabolizers, coadministration with ketoconazole was expected to increase eliglustat Cmax by 4.4-fold and AUC by 5.4-fold per pharmacokinetic modeling simulations. In poor metabolizers taking eliglustat 84 mg/day, concomitant use of ketoconazole was expected to increase eliglustat Cmax 4.3-fold and AUC 6.2-fold 1.
b) Among extensive CYP2D6 metabolizers with Gaucher disease type 1, simulations suggested that eliglustat Cmax would increase 16.7-fold and AUC would increase 24.2-fold with concomitant use of ketoconazole (a strong CYP3A4 inhibitor) plus PARoxetine (a strong CYP2D6 inhibitor). Among intermediate metabolizers, the predicted eliglustat Cmax would increase 7.5-fold and AUC would increase 9.8-fold with concurrent use of ketoconazole plus PARoxetine 1.
Common questions
Can I take Eliglustat and Ketoconazole Topical together?
Increased eliglustat exposure and an increased risk of cardiac arrhythmias from prolongation of the PR, QTc and/or QRS cardiac intervals Always confirm with your pharmacist or prescriber before making any change.
How serious is the Eliglustat 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 Eliglustat 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: CERDELGA(R) oral capsules, eliglustat oral capsules. Genzyme Corporation (per FDA, Cambridge, MA, 2018. DailyMed
Keep reading about Eliglustat
Keep reading about Ketoconazole Topical
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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