[H-3] Latanoprost

Latanoprost is an ester prodrug and synthetic analog of prostaglandin PGF2α formulated as a topical ophthalmic solution. Once absorbed into the cornea, it is hydrolyzed into its active acid form, which selectively stimulates FP prostaglandin receptors in the eye. This binding restructures the extracellular matrix of the ciliary muscle, significantly lowering intraocular pressure (IOP) by increasing fluid drainage.

Latanoprost is a first-line therapy because it achieves powerful, sustained IOP reductions (typically 25–35%) with convenient once-daily dosing. Its superior systemic safety profile, excellent patient compliance, and long-term efficacy in preventing optic nerve damage make it a gold standard for open-angle glaucoma and ocular hypertension.

Latanoprost upregulates specific matrix metalloproteinases (MMPs) within the ciliary body and sclera. These enzymes degrade collagens within the extracellular matrix, creating wider intercellular spaces between ciliary muscle bundles. This structural remodeling significantly reduces hydraulic resistance, allowing aqueous humor to flow more freely out through the non-trabecular, uveoscleral pathway.

The standard recommended dosage is one drop into the affected eye(s) once daily in the evening. Administering the drop at night optimizes its peak therapeutic effect for the morning IOP surge; daily frequency should not be increased, as more frequent dosing actually reduces its pressure-lowering effectiveness.

Common ocular side effects include conjunctival hyperemia (eye redness), mild stinging, hypertrichosis (increased eyelash length, thickness, and darkness), and gradual, potentially permanent hyperpigmentation of the iris and periocular skin. Less frequently, patients may experience foreign body sensation, punctate keratitis, or macular edema (particularly in aphakic or pseudophakic patients).

All three belong to the prostaglandin analog class, but bimatoprost and travoprost often produce slightly greater numerical reductions in IOP compared to latanoprost in clinical trials. However, this marginal efficacy increase with bimatoprost and travoprost is typically accompanied by higher rates of conjunctival hyperemia (eye redness) and hypertrichosis, whereas latanoprost offers a favorable balance of high efficacy and better ocular tolerability.

Yes, latanoprost (such as Xalatan) is approved for lowering IOP in pediatric patients with elevated intraocular pressure or pediatric glaucoma. Clinical studies demonstrate that its safety and efficacy profiles in children aged 1 year and older are generally comparable to those seen in adult populations.

Unopened bottles of latanoprost ophthalmic solution must be stored under refrigeration between 2°C and 8°C and protected from light. Once opened, the bottle may be kept at controlled room temperature up to 25°C for up to 6 weeks before it must be discarded.