Trade names Lumigan MedlinePlus a602030 Routes ofadministration Topical (eye drops) Molar mass 415.566 g/mol | AHFS/Drugs.com Monograph CAS ID 155206-00-1 Protein binding 88% | |
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Pregnancycategory US: C (Risk not ruled out) | ||
Bimatoprost (marketed in the US, Canada and Europe by Allergan, under the trade name Lumigan) is a prostaglandin analog used topically (as eye drops) to control the progression of glaucoma and in the management of ocular hypertension. It reduces intraocular pressure (IOP) by increasing the outflow of aqueous fluid from the eyes. In December 2008, the indication to lengthen eyelashes was approved by the U.S. Food and Drug Administration (FDA); the cosmetic formulation of bimatoprost is sold as Latisse /ləˈtiːs/.
Contents
Medical
Bimatoprost is used for the treatment of open-angle glaucoma and ocular hypertension in adult patients, either alone or in combination with a beta blocker (typically timolol).
Studies have shown bimatoprost to be more effective than timolol in reduction of intraocular pressure (IOP) and as least as effective as the prostaglandin analogs latanoprost and travoprost in reducing IOP.
Cosmetic
In patients using ophthalmic prostaglandins such as travoprost and latanoprost, it has been noted that there had been an increase in diameter, density and length of eyelashes. A study published in May 2010 found that bimatoprost in a gel suspension, when applied at the base of the upper eyelid eyelashes, significantly increased eyelash length. Allergan initiated clinical trials investigating the usage of bimatoprost as a cosmetic drug. In 2008, the FDA Dermatologic and Ophthalmic Drugs Advisory Committee voted to approve bimatoprost for the cosmetic use of darkening and lengthening eyelashes. The medical term for this is treatment of hypotrichosis; however, the FDA approval is for purely cosmetic purposes (see Prostaglandin F receptor#Clinical Significance).
Side effects
Side effects are similar to other prostaglandin analogs applied to the eye. The most common one is conjunctival hyperemia, which occurs in more than 10% of patients. Other effects include blurred vision, eye and eyelid redness, eye burning or other discomfort, and permanent darkening of the iris to brown. Occasional adverse effects (in less than 1% of patients) are headache and nausea.
Some side effects are specific to the cosmetic formulation, which is applied to the skin at the base of the eyelash rather than instilled into the eye. These include infection if the one-time applicators are reused, and darkening of the eyelid or of the area beneath the eye.
Interactions
No interaction studies with this substance have been performed. Interactions with systemic (for example, oral) drugs are considered unlikely because bimatoprost does not reach relevant concentrations in the bloodstream. Bimatoprost does not negatively interact with timolol eye drops.
Mechanism of action
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.