Latanoprost

Latanoprost is a medication primarily used in the treatment of ocular hypertension and open-angle glaucoma, conditions that can lead to vision loss if not properly managed. It is classified as a prostaglandin analogue, which works by increasing the outflow of aqueous humor from the eye, thereby reducing intraocular pressure (IOP). Latanoprost is administered as eye drops.

Mechanism of Action

Latanoprost is a prodrug that is activated through hydrolysis to its acid form, latanoprost acid, after topical application to the eye. The active form of latanoprost acts on the prostaglandin F receptor (FP receptor), increasing the outflow of aqueous humor through the uveoscleral pathway, which in turn reduces intraocular pressure. The reduction of IOP is crucial in preventing optic nerve damage and preserving vision in patients with glaucoma or ocular hypertension.

Pharmacokinetics

After topical application, latanoprost is absorbed through the cornea where it is converted to its active form. Peak concentrations in the aqueous humor are reached about two hours after administration. The systemic absorption of latanoprost is low, and it is primarily metabolized in the liver. The elimination half-life of latanoprost is approximately 17 hours, and it is excreted mainly through the kidneys.

Clinical Use

Latanoprost is indicated for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension. It is often prescribed when other treatments, such as beta-blockers, are not effective or are contraindicated. Latanoprost is typically administered once daily in the evening, which has been shown to be the most effective regimen for reducing IOP.

Side Effects

The most common side effects of latanoprost include conjunctival hyperemia, eye irritation, and changes in eyelash growth. It may also cause a gradual change in the color of the eyes by increasing the amount of brown pigment in the iris. This change may be permanent, especially with long-term use. Less common side effects include blurred vision, eye pain, and the development of a cystoid macular edema.

Comparisons with Other Treatments

Latanoprost has been compared to other IOP-lowering medications, such as timolol, a beta-blocker, and has been found to be equally or more effective in reducing intraocular pressure. Its once-daily dosing and relatively mild side-effect profile make it a preferred choice for many patients.

Formulations and Brands

Latanoprost is available under various brand names, including Xalatan, among others. It is also available in combination with other medications, such as timolol, in products designed to provide an additive effect in lowering IOP.