Bimatoprost

• Approved Indications:
• Open-angle glaucoma and ocular hypertension: To reduce elevated intraocular pressure (IOP) in adults and pediatric patients aged 16 years and older.
• Hypotrichosis of the eyelashes: Treatment to increase eyelash growth including length, thickness, and darkness (marketed as a cosmetic product).
• Off-label / Clinically Accepted Uses:
• Management of other types of glaucoma or ocular hypertension, as determined by specialists.
• Occasionally used off-label for eyebrow hypotrichosis or hair growth stimulation.

• Route: Topical ophthalmic solution (eye drops) or topical application for eyelash growth.
• Ophthalmic Use:
• Instill 1 drop once daily in the affected eye(s) preferably in the evening.
• Do not exceed once daily dosing to avoid reduced efficacy.
• Remove contact lenses prior to administration; wait 15 minutes before reinsertion.
• Eyelash Growth:
• Apply once nightly to the base of the upper eyelashes using the supplied sterile applicator.
• Avoid application to lower eyelid or other skin areas.
• Pediatrics:
• Safety and efficacy established in patients ≥16 years for glaucoma; not established for eyelash growth in children.
• Elderly:
• No dosage adjustment necessary.
• Renal/Hepatic Impairment:
• No dosage adjustments needed; systemic exposure minimal.

Bimatoprost is a synthetic prostamide analog that lowers intraocular pressure by increasing aqueous humor outflow through both the uveoscleral and trabecular meshwork pathways. It acts on prostaglandin FP receptors and possibly other prostamide-sensitive receptors in ocular tissues, promoting extracellular matrix remodeling and increasing outflow facility. For eyelash growth, bimatoprost prolongs the anagen (growth) phase of the hair cycle and increases follicle size, resulting in longer, thicker, and darker lashes.

• Absorption: Minimal systemic absorption after topical ocular administration; peak plasma concentration generally undetectable or very low.
• Distribution: Localized primarily to ocular tissues; systemic distribution negligible.
• Metabolism: Metabolized by ocular and systemic enzymes to inactive metabolites.
• Elimination: Primarily excreted via urine as metabolites.
• Half-life: Systemic elimination half-life approximately 45 minutes; local ocular activity persists longer.
• Onset: Reduction in IOP observed within 4 hours; maximal effect within 8–12 hours.
• Duration: Effect sustained with once-daily dosing.

• Pregnancy: Category C — animal studies have shown adverse effects on the fetus; no adequate human studies. Use only if benefits outweigh risks.
• Lactation: Unknown if excreted in human milk; caution advised; breastfeeding is generally not recommended during treatment.

• Primary Class: Antiglaucoma Agent
• Subclass: Prostaglandin analog / prostamide

• Known hypersensitivity to bimatoprost or any component of the formulation.
• Use caution in patients with active ocular infections.

• May cause iris pigmentation changes, potentially permanent; more common in patients with mixed-color irides.
• Eyelid skin pigmentation may increase and could be reversible.
• Possible growth of eyelashes at unintended sites if the solution contacts surrounding skin.
• Monitor for ocular side effects: conjunctival hyperemia, eye irritation, dryness.
• Avoid contamination of tip to prevent eye infections.
• Use cautiously in patients with uveitis or macular edema.
• Discontinue if signs of ocular inflammation or hypersensitivity occur.

Common:

• Conjunctival hyperemia (redness)
• Eye pruritus and irritation
• Dry eyes
• Eyelash growth or darkening (desired in eyelash treatment; may be undesirable in glaucoma treatment)
• Eye pain or discomfort

Less common / Rare:

• Iris pigmentation changes (usually permanent)
• Eyelid skin darkening
• Periorbital fat atrophy leading to deepening of eyelid sulcus
• Blurred vision
• Headache

• No significant drug-drug interactions reported due to minimal systemic absorption.
• Avoid concurrent use with other topical ocular hypotensive agents unless directed by a physician.

• Guidelines from ophthalmology societies (e.g., American Academy of Ophthalmology) recommend bimatoprost as a first-line agent for lowering IOP in open-angle glaucoma.
• Increased awareness of pigmentation changes and periorbital effects has led to enhanced patient counseling.
• Newer formulations with preservative-free options have been developed to reduce ocular surface irritation.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from light and freezing.
• Keep bottle tightly closed when not in use.
• Discard open bottles after 4 weeks to avoid contamination.
• Keep out of reach of children.