Travoprost, an isopropyl ester prodrug, is a synthetic prostaglandin F2 alpha analogue that is rapidly hydrolyzed by esterases in the cornea to its biologically active free acid. The travoporst free acid is potent and highly selective for the FP prostanoid receptor. Travoprost free acid is a selective FP prostanoid receptor agonist and is believed to reduce intraocular pressure by increasing the drainage of aqueous humor, which is done primarily through increased uveoscleral outflow and to a lesser extent, trabecular outflow facility. Travoprost ophthalmic solution is used for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension who are intolerant of other intraocular pressure lowering medications or insufficiently responsive (failed to achieve target IOP determined after multiple measurements over time) to another intraocular pressure lowering medication. Travoprost is known by the brand names of Travatan and Travatan Z, manufactured by Alcon.

Latanoprost (free acid) is a metabolite of latanoprost which has been approved for use as an ocular hypotensive drug. Latanoprost is an isopropyl ester prodrug which is converted to the Latanoprost-acid by endogenous esterase enzymes. The free acid is pharmacologically active and is 200 times more potent than latanoprost as an agonist of the human recombinant Prostaglandin F receptor. However, the free Latanoprost-acid is more irritating and less effective than Latanoprost when applied directly to the eyes of human glaucoma patients.

Simenepag (AGN-210676) is a a small molecule selective prostaglandin EP2 agonist with EC50 of 5 nM. Allergan was developing simenepag for the treatment of glaucoma and ocular hypertension.

Taprenepag isopropyl (also known as PF-04217329) a prodrug of CP-544326 (active acid metabolite), a potent and selective EP(2) receptor agonist. Taprenepag isopropyl was studied in a clinical trials phase II involving patients with primary open angle glaucoma. According to Pfizer’s pipelines in May 2011, the study was discontinued.

Aganepag isopropyl, an IOP-lowering agent, is an antiglaucoma agent. It is a selective EP2 receptor agonist.