Drug Interaction Report

Latanoprost Ophthalmic and Thimerosal: Interaction Details

Name: Latanoprost Ophthalmic and Thimerosal Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

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

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Latanoprost Ophthalmic

Rocklatan® (as a combination product containing Latanoprost, Netarsudil) Xalatan® Xelpros

Thimerosal

No brand names on record

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Major

Potentially serious — often needs a change or close monitoring.

Minor

Moderate

Major

Contraindicated

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 6 documented Latanoprost Ophthalmic interactions, 5 are rated major — including this one.

Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.

Onset

rapid

Evidence

theoretical

Severity

Major

What happens

Precipitate formation

Interaction Deep Dive

A precipitate occurs when thimerosal-containing eye drops are mixed with latanoprost. If used concomitantly, separate administration by at least 5 minutes apart¹.

Why it happens (mechanism)

Drug incompatibility

Common questions

Can I take Latanoprost Ophthalmic and Thimerosal together?

Precipitate formation Always confirm with your pharmacist or prescriber before making any change.

How serious is the Latanoprost Ophthalmic and Thimerosal interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

Does my dose of Latanoprost Ophthalmic or Thimerosal 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 (1)

Product Information: ROCKLATAN(TM) ophthalmic solution, netarsudil latanoprost ophthalmic solution. Aerie Pharmaceuticals Inc (per manufacturer), Irvine, CA, 2019. DailyMed

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Latanoprost Ophthalmic

Keep reading about Latanoprost Ophthalmic

All Latanoprost Ophthalmic interactions (6) Latanoprost Ophthalmic drug information

Also serious with: Bimatoprost Tafluprost Travoprost Unoprostone

Thimerosal

Keep reading about Thimerosal

All Thimerosal interactions (1)

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