Acetylcysteine 10% ophthalmic solution is a compounded, prescription eye drop of acetylcysteine (also called N-acetylcysteine, or NAC), a mucolytic. A mucolytic thins and loosens mucus. On the eye, acetylcysteine is used to break down mucus and mucus strands, called filaments, that can build up on the ocular surface in some dry-eye conditions. It is prepared by a licensed pharmacy as a sterile eye drop at the strength your eye doctor orders; Bayview offers it at 10%.
Because there is no FDA-approved acetylcysteine eye drop in the United States, eye doctors prescribe it off-label and rely on a compounding pharmacy to prepare it. Only a licensed eye care provider can decide whether it is appropriate.
How does it work?
Mucus gets its thick, sticky structure from bonds (disulfide bonds) that link its proteins together. Acetylcysteine carries a chemical group that breaks those bonds, which thins the mucus and makes it less sticky so it clears from the eye more easily (StatPearls, N-Acetylcysteine). On the ocular surface, this can help loosen the mucus and filaments that form in some dry-eye conditions (EyeWiki, Filamentary Keratitis). Your eye doctor sets the schedule.
What is it used for?
Eye doctors may prescribe acetylcysteine eye drops for conditions in which mucus or filaments build up on the surface of the eye, most classically filamentary keratitis, and for dry-eye disease (keratoconjunctivitis sicca) where mucus is a problem; it has also been studied in meibomian gland dysfunction (Akyol-Salman et al., 2010). It is used off-label because there is no FDA-approved acetylcysteine eye drop in the United States. Only a licensed eye care provider can decide whether it is appropriate; Bayview Pharmacy does not provide consultations or determine appropriateness, and a valid prescription is required.
How is it used?
Use it exactly as your eye doctor directs. A common schedule is one drop in the affected eye or eyes several times a day, often up to four times daily, but your eye doctor sets your own schedule. Wash your hands before use, and do not let the dropper tip touch the eye or any surface. If you wear contact lenses or use other eye drops, ask your eye doctor how to space them. You may notice a mild, sulfur-like smell, which is normal for acetylcysteine. Do not stop or change the schedule on your own; a Bayview pharmacist is available if you have questions about your prescription.
Side effects & safety
The most common effects are local and usually mild, such as brief stinging or burning when the drop goes in, temporary blurred vision, and eye redness or irritation. Because this is a preserved multi-dose drop (it contains benzalkonium chloride), frequent or long-term use can sometimes irritate the ocular surface; your eye doctor will weigh this. Acetylcysteine also has a mild sulfur-like odor, which is expected. Allergic reactions are uncommon.
Contact your eye doctor about eye pain, eye redness that does not go away, or any vision change that concerns you, and seek care for signs of a serious allergic reaction such as rash, swelling, or trouble breathing.
Who should not use it?
Acetylcysteine eye drops are not appropriate for everyone. They should not be used by anyone with a known allergy to acetylcysteine or to any ingredient in the preparation, including the benzalkonium chloride preservative. Tell your eye doctor about the full health history, allergies, contact-lens use, and all medications of the person who will use it, so they can determine whether it is appropriate.
How should it be stored?
Store exactly as directed on your label. This solution is protected from light and is often kept refrigerated, so follow your label. Keep the bottle tightly closed and out of the reach of children, do not share it, and do not touch the dropper tip to the eye or any surface. Because it is a multi-dose sterile drop, discard it 28 days after you first open it, or on the beyond-use date on your label, whichever comes first, and dispose of unused medication as directed.
Why is this compounded?
There is no FDA-approved acetylcysteine eye drop in the United States, so compounding is the way to obtain it. Compounding lets a licensed pharmacy prepare acetylcysteine as a sterile eye drop at the strength your eye doctor orders, such as 10%. As a 503A compounding pharmacy, Bayview Pharmacy prepares each order as a sterile ophthalmic preparation in small batches under USP <797> standards using quality ingredients. Compounded preparations are not FDA-approved.
Clinical details for prescribers
Regulatory status. Acetylcysteine is not a controlled substance. There is no FDA-approved acetylcysteine ophthalmic product in the United States; the ophthalmic form is compounded and prescribed off-label. Compounded preparations are not FDA-approved.
Formulation & SIG. Compounded sterile ophthalmic solution, acetylcysteine 10% (PCCA #7305), preserved with benzalkonium chloride and edetate disodium; hypertonic; protect from light. Prepared under USP <797> sterile-compounding standards. As a preserved multi-dose CSP, the in-use beyond-use date is 28 days after first opening. Typical SIG: 1 drop into the affected eye(s) up to four times daily, or as directed.
Use & evidence:
- Mucolytic action via thiol–disulfide interchange, reducing mucin cross-linking (StatPearls)
- Filamentary keratitis and mucus-related dry-eye disease; adjunct where mucus/filaments impair the ocular surface (EyeWiki)
- Studied in meibomian gland dysfunction (Akyol-Salman 2010); evidence base is limited and largely small studies / clinical experience
- Consider BAK exposure with frequent/long-term dosing; counsel on transient sting and sulfur odor
Ordering: send a prescription to Bayview Pharmacy. Background: EyeWiki, Filamentary Keratitis; Review of Optometry, Fighting Filamentary Keratitis.
This is a prescription compounded medication and is not FDA-approved. This information is educational and is not medical advice. Your eye care provider determines whether it is appropriate and sets the schedule.
