Letermovir Injection and Atorvastatin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Atorvastatin
Letermovir Injection
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 atorvastatin exposure and an increased risk for myopathy and rhabdomyolysis
Interaction Deep Dive
Concomitant use of letermovir and atorvastatin (CYP3A/OATP1B1/OATP1B3 substrate and HMG-CoA reductase inhibitor) is not recommended as it may increase the atorvastatin exposure1. Coadministration of atorvastatin and letermovir increased the AUC of atorvastatin 3.29-fold. If concomitant use is necessary, do not exceed atorvastatin 20 mg daily and closely monitor for signs of myopathy or rhabdomyolysis 12.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of atorvastatin; inhibition of OATP1B1-mediated efflux transport of letermovir; inhibition of OATP1B3-mediated efflux transport of letermovir
Literature reports
2 reports — tap to read
a) In a clinical study, the coadministration of atorvastatin and letermovir in healthy women (n=14) led to increases in atorvastatin AUC(0 to infinity) by 3.29-fold, Cmax by 2.17-fold, and concentration at 24 hours by 3.62-fold compared with atorvastatin alone. Participants received a single oral dose of atorvastatin 20 mg on day 1 of period 1 followed by a 3 day washout period. At the start of period 2, oral letermovir 480 mg was administered once daily on days 1 to 10. A single dose of atorvastatin was coadministered on day 8. Study drugs in both periods were administered following at least 8 hours of fasting and participants continued to fast for at least 4 hours after dosing. Letermovir is an inhibitor of CYP3A, and an OATP1B1, and BCRP transport inhibitor in vitro, while atorvastatin is a substrate of CYP3A, OATP1B1 and possibly BCRP. Since letermovir increased atorvastatin exposure when coadministered, statin-associated adverse events such as myopathy should be closely monitored with concomitant administration 2.
b) In an another drug interaction study, coadministration of letermovir (oral 240 mg once daily) with a CYP3A substrate, midazolam (1 mg single dose IV) led to increased AUC, Cmax and C24hr of midazolam by 47%, 5% and 174%, respectively. And, coadministration of letermovir (oral 240 mg once daily) with midazolam (2 mg single dose orally) led to increased AUC and Cmax of midazolam by 125% and 72%, respectively 1.
Common questions
Can I take Letermovir Injection and Atorvastatin together?
Increased atorvastatin exposure and an increased risk for myopathy and rhabdomyolysis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Letermovir Injection and Atorvastatin 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 "established". Well documented — supported by controlled studies or strong clinical data.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Letermovir Injection or Atorvastatin 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 (2)
- Product Information: PREVYMIS(R) oral tablets, oral pellets, intravenous injection, letermovir oral tablets, oral pellets, intravenous injection. Merck Sharp & Dohme Corp (per FDA), Rahway, NJ, 2024. DailyMed
- McCrea JB, Menzel K, Adedoyin A, et al: Drug-drug interaction of Letermovir and Atorvastatin in healthy participants. Clin Pharmacol Drug Dev 2022; 11(4):420-428. PubMed
Keep reading about Atorvastatin
Keep reading about Letermovir Injection
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