1. Introduction
Latanoprost is a prostaglandin analogue used to lower intraocular pressure (IOP) in conditions such as glaucoma and ocular hypertension. It works by increasing the outflow of aqueous humour through the uveoscleral pathway, reducing IOP.
2. Indications
- Approved Indications:
- Primary open-angle glaucoma.
- Ocular hypertension.
- Off-Label Uses:
- Angle-closure glaucoma (adjunctive therapy).
3. Dosage
- Adults:
- One drop in the affected eye(s) once daily, preferably in the evening.
- Paediatrics:
- Safe for use in children at the same dosage as adults, though monitoring is advised.
4. Administration
- Wash hands before use.
- Tilt head back and gently pull the lower eyelid to create a small pocket. Instil one drop into the pocket without letting the dropper touch the eye or surrounding areas.
- Wait at least 5 minutes before using any other eye drops.
5. Forms Available
- Ophthalmic solution: 0.005% (2.5 mL bottle).
6. Side Effects
6.1. Common Side Effects
- Eye redness (hyperaemia).
- Eye irritation or discomfort.
- Increased pigmentation of the iris (usually permanent).
- Eyelash growth or thickening.
6.2. Less Common Side Effects
- Dry eyes.
- Blurred vision.
- Photophobia.
6.3. Rare but Serious Side Effects
- Macular oedema.
- Eye infections due to improper handling of the bottle.
- Periorbital or eyelid skin darkening (usually reversible).
7. Warnings
- Iris Pigmentation: Latanoprost may cause gradual, permanent changes in iris colour (e.g., blue to brown).
- Herpetic Keratitis: Use cautiously in patients with a history of herpetic keratitis.
- Cystoid Macular Oedema: Rare cases reported, particularly in aphakic or pseudophakic patients.
8. Precautions
- Avoid touching the dropper tip to prevent contamination.
- Use cautiously in patients with uveitis or macular oedema.
- Remove contact lenses before application and reinsert after 15 minutes.
9. Interactions
- Drug-Drug Interactions:
- Use with other prostaglandin analogues may reduce efficacy or cause paradoxical increases in intraocular pressure.
- Drug-Food Interactions:
- None significant.
10. Monitoring Parameters
- Intraocular pressure (regular monitoring to assess efficacy).
- Changes in iris pigmentation or eyelash growth.
- Signs of ocular irritation or infection.
11. Use in Children
- Safe and effective for children; dosage is the same as in adults. Monitor for side effects like eye redness and irritation.
12. Use in Pregnancy
- Category C: Use only if the benefits outweigh the risks. Animal studies have shown potential risks, but human data are limited.
13. Use in Elderly
- Safe for use with no specific dose adjustments required.
14. Use in Kidney Disease
- No dose adjustments required.
15. Use in Liver Disease
- No dose adjustments required.
16. Patient Counselling Points
- Instil latanoprost once daily in the evening for the best results.
- Avoid overuse, as more frequent dosing may reduce its effectiveness.
- Report any persistent eye redness, pain, or changes in vision to your doctor.
- Be aware that iris colour and eyelash changes are possible and may be permanent.
- Remove contact lenses before applying and wait 15 minutes before reinserting.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Xalatan | Pfizer | $60–100 (2.5 mL) |
Generic Latanoprost | Various manufacturers | $20–50 (2.5 mL) |
18. FAQs (15 Questions)
- What is latanoprost used for?
It is used to lower intraocular pressure in glaucoma and ocular hypertension. - How does latanoprost work?
It increases the outflow of aqueous humour from the eye, reducing intraocular pressure. - When should I use latanoprost?
It is best used in the evening to maximise its efficacy. - Can latanoprost change eye colour?
Yes, it may cause permanent darkening of the iris, especially in people with mixed-colour eyes. - How long does latanoprost take to work?
Maximum effect is usually seen within 8–12 hours after application, with continued improvement over weeks. - Can latanoprost cause eyelash growth?
Yes, it can cause eyelashes to grow longer, thicker, and darker. - Is latanoprost safe during pregnancy?
It is classified as Category C and should only be used if the benefits outweigh the risks. - Can latanoprost be used with contact lenses?
Remove lenses before use and wait at least 15 minutes before reinserting them. - Can latanoprost cause side effects?
Common side effects include eye redness, irritation, and eyelash changes. - What should I do if I miss a dose?
Instil the missed dose as soon as possible unless it is close to the next dose. Do not double the dose. - Can I use latanoprost more than once daily?
No, more frequent use can reduce its effectiveness. - Does latanoprost interact with other eye drops?
Using other prostaglandin analogues may reduce its efficacy. - How should latanoprost be stored?
Store unopened bottles in the refrigerator. After opening, store at room temperature and use within 6 weeks. - Can children use latanoprost?
Yes, it is safe and effective for children at the same dose as adults. - Is latanoprost available as a generic?
Yes, generic versions are widely available and more affordable.