Ciprofloxacin and Avanafil: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ciprofloxacin
No brand names on recordAvanafil
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 avanafil exposure
Interaction Deep Dive
Concomitant use of moderate CYP3A4 inhibitors, and avanafil, a CYP3A4 substrate, may result in increased plasma concentrations of avanafil. Avanafil Cmax and AUC increased 2-fold and 3.6-fold, respectively, when a single 200-mg dose of avanafil was coadministered with erythromycin 500 mg twice daily (also a moderate CYP3A4 inhibitor) in a study of 15 healthy volunteers. Avanafil doses should not exceed 50 mg once every 24 hours in patients taking moderate CYP3A4 inhibitors1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated avanafil metabolism
Literature reports
1 report — tap to read
a) In an open-label, randomized, one-sequence crossover, three-way parallel study, fifteen healthy male volunteers received 500 mg erythromycin (2 tablets containing 250 mg erythromycin) every 12 hours for 5 days (Days 2 to 6) and a single 200 mg avanafil (2 tablets containing 100 mg avanafil) on Days 1 and 6. Twenty-four hour pharmacokinetics of avanafil on Days 1 and 6 were compared. Coadministration with the moderate CYP3A4 inhibitor erythromycin resulted in an approximate 3.6-fold increase in AUC (0 to inf) and 2-fold increase in Cmax of avanafil, and prolonged the half-life of avanafil to approximately 8 hours 1.
Common questions
Can I take Ciprofloxacin and Avanafil together?
Increased avanafil exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ciprofloxacin and Avanafil interaction?
It is rated moderate. Can be significant — usually manageable with 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 "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 Ciprofloxacin 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: STENDRA(R) oral tablets, avanafil oral tablets. Metuchen Pharmaceuticals LLC (per FDA), Freehold, NJ, 2022. DailyMed
Keep reading about Ciprofloxacin
Keep reading about Avanafil
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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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