Lovastatin and Ritonavir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ritonavir
Lovastatin
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 lovastatin exposure and an increased risk of lovastatin-related adverse effects, such as an increased risk of myopathy or rhabdomyolysis
Interaction Deep Dive
Lovastatin is metabolized by CYP3A4 enzymes, and ritonavir is a known potent inhibitor of CYP3A4. Coadministered ritonavir may significantly increase lovastatin exposure, resulting in lovastatin toxicity. Concomitant use is contraindicated due to the potential for an increased risk of myopathy with possible rhabdomyolysis123. If treatment with nirmatrelvir/ritonavir is considered medically necessary, discontinue use of lovastatin at least 12 hours prior to initiation of nirmatrelvir/ritonavir, during the 5 days of nirmatrelvir/ritonavir treatment, and for 5 days after completing nirmatrelvir/ritonavir 4. If treatment with ritonavir is unavoidable, suspend lovastatin during the course of ritonavir treatment. In a drug interaction study, coadministration of itraconazole (strong CYP3A4 inhibitor) and lovastatin increased lovastatin AUC and Cmax by 14.8-fold and 14.5-fold, respectively 1.
Why it happens (mechanism)
Inhibition of OATP1B1-mediated efflux transport of lovastatin; inhibition of CYP3A4-mediated lovastatin metabolism
Literature reports
1 report — tap to read
a) In a drug interaction study, coadministration of itraconazole (strong CYP3A4 inhibitor) and lovastatin increased lovastatin AUC and Cmax by 14.8-fold and 14.5-fold, respectively 1.
Common questions
Can I take Lovastatin and Ritonavir together?
Increased lovastatin exposure and an increased risk of lovastatin-related adverse effects, such as an increased risk of myopathy or rhabdomyolysis Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lovastatin and Ritonavir interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
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 Lovastatin or Ritonavir 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 (4)
- Product Information: ALTOPREV(R) oral extended-release tablets, lovastatin oral extended-release tablets. Covis Pharma (per FDA), King of Prussia, PA, 2024. DailyMed
- Product Information: NORVIR(R) oral capsules, oral solution, ritonavir oral capsules, oral solution. Abbott Laboratories, North Chicago, IL, 2009. DailyMed
- Product Information: KALETRA(R) film coated oral tablets, oral solution, lopinavir and ritonavir film coated oral tablets, oral solution. Abbott Laboratories, North Chicago, IL, 2009.
- Product Information: PAXLOVID(TM) oral tablets, nirmatrelvir oral tablets, ritonavir oral tablets. Pfizer Labs (per FDA), New York, NY, 2025. DailyMed
Keep reading about Ritonavir
Keep reading about Lovastatin
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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:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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