Posaconazole and Fluvastatin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Posaconazole
Fluvastatin
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 fluvastatin plasma concentration and increased risk of myopathy or rhabdomyolysis
Interaction Deep Dive
Concomitant use of fluvastatin and posaconazole is contraindicated. Although the potential for an interaction between fluvastatin (a CYP3A4 substrate) and posaconazole (a strong CYP3A4 inhibitor) has not been studied, concomitant use of posaconazole and simvastatin (another HMG-CoA reductase inhibitor and CYP3A4 substrate) resulted in significant increases in simvastatin Cmax and AUC. It is feasible that concomitant use of fluvastatin and posaconazole may result in increased fluvastatin plasma concentrations, which may lead to rhabdomyolysis1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated fluvastatin metabolism by posaconazole
Literature reports
1 report — tap to read
a) In clinical trials of healthy volunteers, coadministration of simvastatin and posaconazole resulted in significant increases in simvastatin Cmax and AUC. When a single, 40 mg simvastatin dose was coadministered to subjects receiving posaconazole oral suspension 100 mg once daily for 13 days, the simvastatin mean Cmax and AUC increased by 841% and 931%, respectively. Simvastatin acid Cmax and AUC increased by 817% and 634%. When simvastatin was coadministered at the same dose with posaconazole suspension at a dose of 200 mg once daily for 13 days, the simvastatin mean Cmax and AUC increased by 1041% and 960%. Simvastatin acid Cmax and AUC increased by 851% and 748% 1.
Common questions
Can I take Posaconazole and Fluvastatin together?
Increased fluvastatin plasma concentration and increased risk of myopathy or rhabdomyolysis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Posaconazole and Fluvastatin interaction?
It is rated contraindicated. These should generally not be used together.
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 Posaconazole or Fluvastatin 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: NOXAFIL(R) intravenous injection, oral delayed-release tablets, oral suspension, posaconazole intravenous injection, oral delayed-release tablets, oral suspension. Merck Sharp & Dohme Corp. (per FDA), Whitehouse Station, NJ, 2016. DailyMed
Keep reading about Posaconazole
Keep reading about Fluvastatin
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