Drug Interaction Report

Acyclovir Ophthalmic and Probenecid: Interaction Details

A pharmacist-reviewed analysis of the Acyclovir Ophthalmic and Probenecid interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Probenecid

No brand names on record
+

Acyclovir Ophthalmic

Avaclyr Avaclyr® Sitavig Zovirax
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Jul 10, 2026
Editorial policy · Data sources
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
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.

Of 24 documented Acyclovir Ophthalmic interactions, 5 are rated moderate — including this one.
Onset
unspecified
Evidence
theoretical
Severity
Moderate

What happens

Increased OAT3 substrate exposure

Interaction Deep Dive

Coadministration of probenecid and OAT3 substrates may increase exposure of OAT3 substrates1.

Why it happens (mechanism)

Inhibition of OAT3-mediated efflux transport by probenecid

Literature reports

1 report — tap to read

a) A study found that coadministration of probenecid (1500 mg) with famotidine (20 mg) resulted in significant increases in area under the famotidine serum concentration-time curve up to 10 hours (from 420 to 760 ng-h/mL) and maximum serum concentration (from 73 to 112 ng/mL), with decreases in renal clearance of famotidine. After receiving an oral dose of famotidine 20 mg and determination of resulting pharmacokinetic parameters, 8 healthy subjects serving as their own controls underwent a 30 day washout period before the concomitant administration of probenecid 1500 mg (1000 mg 2 hrs prior, 250 mg 1 hr prior, and 250 mg simultaneously) and famotidine 20 mg. The data strongly support the ability of probenecid to inhibit the renal tubular secretion of famotidine 2.

Common questions

Can I take Acyclovir Ophthalmic and Probenecid together?

Increased OAT3 substrate exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Acyclovir Ophthalmic and Probenecid 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 Acyclovir Ophthalmic or Probenecid 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 (2)

  1. Product Information: ORLYNVAH(TM) oral tablets, sulopenem etzadroxil and probenecid oral tablets. Iterum Therapeutics U.S. Limited (per FDA), Chicago, IL, 2024. DailyMed
  2. Inotsume N, Nishimura M, Nakono M, et al: The inhibitory effect of probenecid on renal excretion of famotidine in young, healthy volunteers. J Clin Pharmacol 1990; 30:50-56. PubMed
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Probenecid

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Acyclovir Ophthalmic

Keep reading about Acyclovir Ophthalmic

All Acyclovir Ophthalmic interactions (24) Acyclovir Ophthalmic drug information
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Beyond drug–drug

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:

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major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.