Lopinavir and Avanafil: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Avanafil
Lopinavir
No brand names on record
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
Decreased avanafil clearance and increased avanafil plasma concentration
Interaction Deep Dive
Concomitant administration of lopinavir/ritonavir (ritonavir is a strong CYP3A4 inhibitor)2 and avanafil (a CYP3A4 substrate) may result in increased avanafil exposure and toxicity. Compared with the pharmacokinetics of avanafil alone, the administration of a single dose of avanafil 50 mg with ritonavir 600 mg twice daily resulted in a 13-fold increase in AUC, 2.4-fold increase in Cmax, and a prolonged half-life of 9 hours for avanafil. Lopinavir/ritonavir and avanafil should not be used concomitantly 1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of avanafil by lopinavir/ritonavir
Literature reports
1 report — tap to read
a) Compared with the pharmacokinetics of avanafil alone, the administration of a single dose of avanafil 50 mg with ritonavir 600 mg twice daily resulted in a 13-fold increase in AUC, 2.4-fold increase in Cmax, and a prolonged half-life of 9 hours for avanafil in healthy volunteers (n=14). Subjects received a single dose of avanafil 50 mg (Day 1) followed by ritonavir 300 mg twice daily (Day 2), ritonavir 400 mg twice daily (Day 3), and ritonavir 600 mg twice daily (Days 4 to 8) on consecutive days. After the administration of a second dose of avanafil 50 mg on Day 8, the 24-hour pharmacokinetic profile was compared to baseline 1.
Common questions
Can I take Lopinavir and Avanafil together?
Decreased avanafil clearance and increased avanafil plasma concentration Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lopinavir and Avanafil 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Lopinavir or Avanafil 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: STENDRA(R) oral tablets, avanafil oral tablets. Metuchen Pharmaceuticals LLC (per FDA), Freehold, NJ, 2022. DailyMed
- Product Information: KALETRA oral film coated tablets, oral solution, lopinavir ritonavir oral film coated tablets, oral solution. Abbott Laboratories (Per manufacturer), North Chicago, IL, 2012. DailyMed
Keep reading about Avanafil
Keep reading about Lopinavir
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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:
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