Xalatan (Latanoprost)

What latanoprost is and how it works

Xalatan (latanoprost) is a prostaglandin eye drop used once daily to lower elevated pressure inside the eye (intraocular pressure, IOP) in open-angle glaucoma and ocular hypertension, by increasing natural fluid outflow from the eye. (2) (7)

Latanoprost is generally well tolerated and has no boxed warning, but it has two real, well-documented effects worth knowing about before starting. First, it can cause a gradual, likely permanent increase in brown pigmentation of the iris (the coloured part of the eye), especially in eyes with mixed colouring -- this is a cosmetic change, not a sign the medicine is harming the eye, but it will not reverse if you stop treatment. Second, prolonged use can cause changes around the eye socket itself (deepening of the upper eyelid crease, slight sinking of the eye, tightened eyelids) from gradual fat loss around the eye -- a real, documented effect of this drug class that is usually reversible if the medicine is stopped. Eyelash growth and periorbital skin darkening can also occur and are usually reversible.

Mechanism of action: how latanoprost works

Latanoprost is a prodrug hydrolysed by corneal esterases to its biologically active acid form, a selective prostaglandin F2-alpha (FP) receptor agonist. It lowers intraocular pressure primarily by increasing uveoscleral outflow of aqueous humour, a distinct mechanism from beta-blockers and other older IOP-lowering classes. (6)

What latanoprost is used for

Before taking latanoprost

Do not take / not appropriate for

• Do not use if you have a known hypersensitivity (allergic) reaction to latanoprost, benzalkonium chloride, or any other ingredient in this product. (all countries) (1)
• Avoid use during an active herpes simplex (cold sore virus) eye infection. (all countries) (2)

Tell your clinician about

• Any past episode of iritis or uveitis (inflammation inside the eye), or active eye inflammation.
• If you do not have a natural lens in the treated eye (aphakic) or have an artificial lens with a torn posterior capsule, or any other risk factor for macular oedema (swelling at the back of the eye).
• Any past history of herpes simplex keratitis (cold-sore-virus eye infection).
• Any history of asthma or breathing problems, since asthma flare-ups and breathlessness have been reported.
• If you wear contact lenses -- these should be removed before applying the drops and can be reinserted after 15 minutes.
• Any other eye drops you use, especially another prostaglandin-type eye drop, since using two together is not recommended and can paradoxically raise eye pressure.
• If you are pregnant, planning pregnancy, or breastfeeding.

How to take latanoprost

• Use exactly one drop in the affected eye(s) once daily -- using it more often than once a day can reduce how well it works and may even raise eye pressure instead of lowering it.
• The best effect is usually obtained when the dose is given in the evening.
• If using other eye drops at the same time, space them at least 5 minutes apart.
• Remove contact lenses before applying the drops; they can be put back in after 15 minutes.
• Wash your hands before use and avoid letting the dropper tip touch your eye or any other surface, to reduce the risk of contamination and eye infection.

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7)

Missed dose

If a dose is missed, continue with the next regularly scheduled dose the following day. Do not use an extra drop to make up for a missed dose -- using it more than once daily can reduce its effect or raise eye pressure. Ask your pharmacist or clinician if you are unsure.

Overdose

Ocular overdose (too many drops at once) may cause temporary eye irritation, redness, or watering; rinse the eye with lukewarm water and contact a clinician or pharmacist if irritation persists. If the product is accidentally swallowed, contact a doctor or poison control centre for advice. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Serious warnings

Interactions

• Other prostaglandin-type eye drops (prostaglandins, prostaglandin analogues, or prostaglandin derivatives): using two or more together is not recommended, as it has been linked to a paradoxical increase in eye pressure rather than a further decrease. (2)
• Other topical eye drops: if using more than one type, space them at least 5 minutes apart to avoid one washing out the other. (1)
• Thimerosal-containing eye drops: may precipitate (form particles) if physically mixed with latanoprost -- avoid direct mixing. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Monitoring

Before starting

• Baseline eye examination including iris colour and eyelid/periorbital appearance, for later comparison.
• Review of any history of uveitis/iritis, macular oedema risk factors, herpes keratitis, or asthma.
• Confirm no other prostaglandin-type eye drop is being used concurrently.

During treatment

• Periodic eye pressure checks to confirm the medicine is working as intended.
• Watch for gradual iris colour change, eyelid/periorbital changes, or new eye inflammation, and report these to your eye clinician.
• Report any new asthma symptoms or breathing difficulty.

Storage

Store as directed on the product label (unopened bottles typically require refrigeration; once opened, many latanoprost products can be kept at room temperature for a limited time -- check your specific product's leaflet). Keep out of reach of children, and discard any opened bottle after the period stated on the label.

Frequently asked questions

References

1. XALATAN (latanoprost ophthalmic solution) 0.005% -- full prescribing informationDailyMed (U.S. National Library of Medicine) / FDA-approved prescribing information · United States · accessed 2026-07-30 · source 1
2. Xalatan 50 micrograms/ml eye drops, solution -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Summary of Product Characteristics · United Kingdom · accessed 2026-07-30 · source 2
3. Latanoprost -- list of nationally authorised medicinal products (PSUSA/00001832)European Medicines Agency (EMA) -- PSUSA periodic safety update assessment / list of nationally authorised medicinal products · European Union · accessed 2026-07-30 · source 3
4. XALATAN (latanoprost) -- DIN 02231493, product monographHealth Canada -- Drug Product Database (DIN) / product monograph · Canada · accessed 2026-07-30 · source 4
5. XALATAN latanoprost 50 microgram/mL eye drops -- ARTG entry 58775Therapeutic Goods Administration (TGA), Australia -- Australian Register of Therapeutic Goods (ARTG) · Australia · accessed 2026-07-30 · source 5
6. XALATAN Eye Drops (Latanoprost 50 micrograms/mL) -- New Zealand Data SheetMedsafe (New Zealand regulator) -- New Zealand Data Sheet · New Zealand · accessed 2026-07-30 · source 6
7. Periorbital muscle/fat atrophy associated with topical prostaglandin analogue therapy (Prostaglandin-Associated Periorbitopathy, PAP)peer-reviewed ophthalmology literature (PMC) · international / clinical literature · accessed 2026-07-30 · source 7

Brand names by country

Single-ingredient latanoprost names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries