Simvastatin and Eltrombopag: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 4, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Eltrombopag
Simvastatin
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.
These two medicines can interact. Eltrombopag can slow down one of the doorways your body uses to pull simvastatin out of your blood and into your liver. When that doorway is blocked, more simvastatin can build up in your body.
Higher simvastatin levels raise the chance of muscle side effects. Watch for unexplained muscle pain, tenderness, weakness, or dark-colored urine. Rarely, a serious muscle problem called rhabdomyolysis can happen. The good news is that this concern is based mostly on how the drugs work, not on lots of real-world reports. Your care team can manage this by keeping an eye on you and adjusting your simvastatin dose if needed. Please talk with your pharmacist or doctor before making any changes.
Effect: Eltrombopag inhibits OATP1B1 and BCRP, transporters that mediate hepatic uptake and efflux of simvastatin (an OATP1B1 substrate). Reduced transport increases simvastatin plasma exposure, raising the risk of myopathy and rhabdomyolysis. Direction: increased statin effect/toxicity.
- Mechanism: OATP1B1 and BCRP transporter inhibition (PK interaction).
- Onset: unspecified.
- Evidence: theoretical; magnitude not quantified.
- Management: Use caution if coadministered. Monitor for muscle symptoms and CK if indicated; consider reducing the simvastatin dose, individualized to the patient. Counsel on myopathy warning signs.
What happens
Increased risk of simvastatin toxicity, including an increased risk of myopathy or rhabdomyolysis
Interaction Deep Dive
Exercise caution3 when eltrombopag, which inhibits OATP1B1, is given together with simvastatin, an OATP1B1 substrate, because the combination can raise simvastatin plasma levels and heighten the likelihood of myopathy, such as rhabdomyolysis 123. Watch patients for signs of toxicity and think about lowering the simvastatin dose 23.
Why it happens (mechanism)
Inhibition of OATP1B1-mediated simvastatin transport by eltrombopag; inhibition of BCRP-mediated simvastatin transport by eltrombopag
How to manage this interaction
If you have been prescribed both, keep taking them as directed unless your prescriber tells you otherwise. This interaction is usually manageable.
- Closer monitoring: Your care team may watch you more closely for muscle symptoms.
- Dose: Your simvastatin dose may be reduced and individualized by your care team if you need both medicines.
- Report promptly: Tell your pharmacist or doctor about new or worsening muscle pain, tenderness, weakness, or dark or reddish urine.
Do not start, stop, or change either medicine on your own. Ask your pharmacist or prescriber if you have questions.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
Common questions
Can I take Simvastatin and Eltrombopag together?
Eltrombopag can raise simvastatin levels and increase the risk of muscle problems, so your team may lower your simvastatin dose and watch for muscle pain. Keep taking both as prescribed and report muscle symptoms right away. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Simvastatin and Eltrombopag 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 Simvastatin and Eltrombopag interaction managed?
If you have been prescribed both, keep taking them as directed unless your prescriber tells you otherwise. This interaction is usually manageable. Closer monitoring: Your care team may watch you more closely for muscle symptoms. Dose: Your simvastatin dose may be reduced and individualized by your care team if you need both medicines. Report promptly: Tell your pharmacist or doctor about new or wo… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Simvastatin or Eltrombopag 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 (3)
- Product Information: ZOCOR(R) oral tablets, simvastatin oral tablets. Merck Sharp & Dohme Corp. (per FDA), Whitehouse Station, NJ, 2015. DailyMed
- Product Information: ALVAIZ(TM) oral tablets, eltrombopag oral tablets. TEVA Pharmaceuticals (per FDA), Parsippany, NJ, 2023. DailyMed
- Product Information: PROMACTA(R) oral tablets, oral suspension, eltrombopag oral tablets, oral suspension. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
Keep reading about Eltrombopag
Keep reading about Simvastatin
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