Bimatoprost is a structural analog of prostaglandin F2α (PGF2α). Like other PGF2α analogs such as travoprost, latanoprost and tafluprost, it increases the outflow of aqueous fluid from the eye and lowers intraocular pressure. However, in contrast to these it does not act on the prostaglandin F receptor, nor on any other known prostaglandin receptor. It is thought that bimatoprost mimics the human body’s own prostamides (which are chemically similar), a class of substances related to prostaglandins, but with an unknown mechanism of action. No prostamide receptor has been identified as of 2015; the search is ongoing.
Pharmacokinetics:Bimatoprost is well absorbed through the cornea. It starts lowering intraocular pressure after four hours, lasting for at least 24 hours. A low percentage enters the bloodstream. In the blood plasma, peak concentrations are reached after 10 minutes, then drop below the detection limit of 25 pg/ml after 1.5 hours. The substance does not accumulate in the body.
Plasma protein binding is 88%. Bimatoprost is metabolized by oxidation, N-deethylation and glucuronidation, forming a variety of metabolites. Biological half-life was measured to be 45 minutes after intravenous infusion. 67% are eliminated via the kidney, and 25% via the feces.