Sirolimus and Abrocitinib: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sirolimus
Abrocitinib
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.
Here's what's going on: Sirolimus (Rapamune) is a medicine that quiets your immune system, and it's one that needs to stay in a fairly narrow range in your blood. Abrocitinib (Cibinqo) can block a 'pump' in your body called P-glycoprotein that normally helps move sirolimus out. When that pump is slowed, more sirolimus can build up, which could mean stronger side effects like infections, mouth sores, or changes in your blood counts.
The good news: this is based on how the drugs work in theory, not on lots of real-world reports. Your care team can manage it easily by checking your sirolimus levels and adjusting your dose. Don't change anything on your own, just talk with your doctor or pharmacist.
Mechanism: Abrocitinib inhibits P-glycoprotein (P-gp)-mediated efflux. Sirolimus is a P-gp substrate, so coadministration may increase sirolimus exposure (AUC/Cmax).
Direction: Increased sirolimus effect and toxicity risk. Sirolimus is a narrow-therapeutic-index agent, so even modest exposure increases matter.
- Severity: Major
- Evidence: Theoretical (based on P-gp interaction potential)
- Onset: Unspecified
Management: If coadministration is necessary, monitor sirolimus whole-blood trough levels and titrate the dose. Watch for immunosuppression-related toxicity (myelosuppression, infection, mucositis, metabolic changes). Individualize dosing per levels and clinical response.
What happens
Increased exposure of P-glycoprotein substrate
Interaction Deep Dive
When a P-gp substrate that has a narrow therapeutic index (for example, digoxin) is given together with abrocitinib, which inhibits P-gp, the substrate's exposure may rise. Should concurrent use be required, apply suitable monitoring or titrate the dose of the P-gp substrate in cases where minor shifts in concentration can produce serious or life-threatening toxicities1.
Why it happens (mechanism)
Inhibition of P-glycoprotein-mediated efflux transport by abrocitinib
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. This interaction is manageable with the right follow-up.
- Your team may check your sirolimus blood levels more closely when abrocitinib is started, stopped, or changed.
- Your sirolimus dose may be adjusted and individualized by your care team based on those levels.
- Watch for and report signs like unusual infections, fever, mouth sores, easy bruising, or feeling very run down.
Bring this up with your pharmacist or prescriber so they can plan the monitoring, especially since sirolimus needs to stay in a tight range.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Sirolimus and Abrocitinib together?
Abrocitinib may raise sirolimus levels by blocking a transport pump, and because sirolimus has a narrow safe range, your care team should monitor your sirolimus levels and adjust the dose. Keep taking both as prescribed and check in with your pharmacist or doctor. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sirolimus and Abrocitinib 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 is the Sirolimus and Abrocitinib interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. This interaction is manageable with the right follow-up. Your team may check your sirolimus blood levels more closely when abrocitinib is started, stopped, or changed. Your sirolimus dose may be adjusted and individualized by your care team based on those levels. Watch for and report signs like unusual infections,… Management is individual — always follow your own care team's guidance.
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 Sirolimus or Abrocitinib 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: CIBINQO(TM) oral tablets, abrocitinib oral tablets. Pfizer Labs (per FDA), New York, NY, 2022. DailyMed
Keep reading about Sirolimus
Keep reading about Abrocitinib
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:
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.
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