Short answer: In the label's trials against timolol eye drops, the most common Xalatan side effects were a foreign body feeling in the eye (13% vs 8%), punctate keratitis (10% vs 9%), stinging (9% vs 12%), eye redness (8% vs 3%), blurred vision, itching, burning and darker iris color (7% vs 0%). The darker iris is likely permanent. There is no boxed warning.
What Xalatan is approved for: Xalatan is a prostaglandin F2-alpha analogue eye drop approved to lower raised pressure inside the eye (intraocular pressure, IOP) in people with open-angle glaucoma or ocular hypertension (section 1).
Source
XALATAN (latanoprost ophthalmic solution) 0.005%, prescribing information. Viatris Specialty. DailyMed, version published October 25, 2024. DailyMed setid a98595b3-9f47-48e0-b18d-550a2095f264
No. The current Xalatan label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Xalatan.
| Symptom/Finding | Latanoprost (%) n=460 | Timolol (%) n=369 |
|---|---|---|
| Foreign body sensation | 13 | 8 |
| Punctate keratitis | 10 | 9 |
| Stinging | 9 | 12 |
| Conjunctival hyperemia | 8 | 3 |
| Blurred vision | 8 | 8 |
| Itching | 8 | 8 |
| Burning | 7 | 8 |
| Increased pigmentation of the iris | 7 | 0 |
From three randomized trials of Xalatan once daily vs timolol 5 mg/mL twice daily (another glaucoma eye drop, not placebo). Mean age 65 years; 7% withdrew before the 6-month endpoint.
| Adverse reaction | Latanoprost (%) n=460 | Timolol (%) n=369 |
|---|---|---|
| Excessive tearing | 4 | 6 |
| Eyelid discomfort/pain | 4 | 2 |
| Dry eye | 3 | 3 |
| Eye pain | 3 | 3 |
| Eyelid margin crusting | 3 | 3 |
| Erythema of the eyelid | 3 | 2 |
| Photophobia | 2 | 1 |
| Eyelid edema | 1 | 3 |
| Blepharitis | 1 | 3 |
| Upper respiratory tract infection/nasopharyngitis/influenza (systemic) | 3 | 3 |
| Myalgia/arthralgia/back pain (systemic) | 1 | 0.5 |
| Rash/allergic skin reaction (systemic) | 1 | 0.3 |
Same three trials. Conjunctival hyperemia means eye redness; punctate keratitis means tiny spots of irritation on the clear front of the eye.
Less than 1% of patients on Xalatan stopped treatment because they could not tolerate eye redness.
In a 3-year safety study with a 2-year extension (519 patients, 380 in the extension), most people who developed noticeably darker irises did so within the first year, and the darkening kept increasing through the 5 years of the study. Pressure lowering was similar whether or not it occurred.
Reported after approval: dizziness, headache, toxic epidermal necrolysis, deepening of the eyelid crease, iris cyst, eyelid skin darkening, conjunctivitis, asthma or worse asthma, shortness of breath, nausea, vomiting, herpes keratitis, angina, palpitations and chest pain.
In healthy volunteers, IV latanoprost up to 3 mcg/kg caused no adverse reactions; IV doses of 5.5 to 10 mcg/kg caused abdominal pain, dizziness, fatigue, hot flushes, nausea and sweating.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Pigmentation. Xalatan can darken the iris, the eyelid skin and the eyelashes, and this keeps increasing while it is used. Iris darkening is likely permanent after stopping; eyelid and eyelash changes have reversed in some people. Iris change may not be noticeable for months to years. Effects beyond 5 years are not known.
Eyelash changes. Eyelashes and fine hair in the treated eye may become longer, thicker, darker and more numerous, or grow in the wrong direction. These changes usually reverse after stopping.
Inflammation inside the eye. Used with caution after past iritis or uveitis, and generally not used during active inflammation inside the eye, because it may make it worse.
Macular edema. Swelling of the macula, including cystoid macular edema, has been reported. Caution is used after cataract surgery without a lens implant, with a torn posterior lens capsule, or with other known risk factors.
Herpes keratitis. Reactivation of herpes simplex infection of the cornea has been reported. Xalatan is avoided during active herpes keratitis and used with caution with a past history.
Bacterial keratitis. Multiple-dose eye drop bottles can become contaminated, mostly in people who already had cornea problems, and this has led to bacterial infections of the cornea.
Contact lenses. Xalatan contains the preservative benzalkonium chloride, which may be absorbed by contact lenses. Lenses are removed before the drop and may go back in 15 minutes later.
From the Patient Counseling Information (section 17) that comes with Xalatan:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.