Pharmacology Of Bimatoprost

Indication	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.
Pharmacodynamics	Bimatoprost is a prostamide, a synthetic structural analog of prostaglandin with ocular hypotensive activity, that is chemically related to prostamide F. It selectively mimics the effects of naturally occurring substances, prostamides. Bimatoprost lowers intraocular pressure (IOP) in humans. Elevated IOP presents a major risk factor for glaucomatous field loss. The higher the level of IOP, the greater the likelihood of optic nerve damage and visual field loss.
Mechanism of action	Bimatoprost is believed to lower intraocular pressure (IOP) in humans by increasing outflow of aqueous humor through both the trabecular meshwork and uveoscleral routes. Bimatoprost reduces the pressure in the eye by mimicking the action of a naturally-occuring prostaglandin. Prostaglandins are a group of chemicals found in many places in the body. In the eye, they increase the drainage of the aqueous humour out of the eyeball. Bimatoprost is a synthetic compound related to one of the natural prostaglandins, and works by increasing the drainage of aqueous humour out of the eyeball. Bimatoprost may also lower the rate of aqueous formation in the eye. Both these effects decrease the pressure within the eye.
Absorption	Systemically absorbed when administered to the eye.
Volume of distribution	0.67 L/kg
Protein binding	Approximately 88% of bimatoprost is bound in human plasma.
Metabolism	Bimatoprost undergoes oxidation, N-deethylation and glucuronidation to form a variety of metabolites.
Route of elimination	Up to 67% of the administered dose was excreted in the urine while 25% of the dose was recovered in the feces.
Half life	Elimination half-life is approximately 45 minutes.
Clearance	1.5 L/hr/kg [Healthy subjects receiving IV administration of 3.12 ug/kg]
Toxicity	In oral (by gavage) mouse and rat studies, doses up to 100 mg/kg/day did not produce any toxicity. This dose expressed as mg/m2 is at least 70 times higher than the accidental dose of one bottle of bimatoprost for a 10 kg child.