Avost0.004%

Avost 0.004% ophthalmic solution is a prostaglandin analogue indicated for the reduction of elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension.

Contains Avost 0.004% 0.004% (0.04 mg/mL) as the active ingredient in a sterile ophthalmic solution, commonly preserved with benzalkonium chloride.

Avost 0.004% is a once-daily prostaglandin analogue eye drop used to lower the pressure inside the eye in patients with open-angle glaucoma or ocular hypertension, conditions where raised eye pressure can gradually damage the optic nerve and lead to vision loss if untreated. It works by increasing the outflow of fluid from the eye. Avost 0.004% is well known for causing a gradual, and often permanent, increase in brown pigmentation of the iris, along with reversible changes to the eyelashes and eyelid skin, which patients should be counselled about before starting treatment.

Therapeutic Class: Ophthalmic Antiglaucoma Agent (Prostaglandin Analogue)

Avost 0.004% is a prodrug that is hydrolyzed by esterases in the cornea to its biologically active free acid form after topical application. This active form increases uveoscleral outflow of aqueous humour from the eye, which is the primary mechanism by which it lowers intraocular pressure, and its once-daily dosing reflects a sustained duration of action on this outflow pathway.

• Instill 1 drop into the affected eye(s) once daily, in the evening, as directed
• Wash hands before use; avoid touching the dropper tip to the eye or any surface, to prevent contamination
• Remove contact lenses before instillation; they may be reinserted 15 minutes after the drop is given
• If using more than one eye medicine, space each by at least 5 minutes
• Do not exceed one dose per 24 hours

Systemic absorption from topical ophthalmic use is generally minimal, so significant systemic drug interactions are uncommon. If other eye medicines are used at the same time, space doses at least 5 minutes apart, and discuss with a doctor or pharmacist if combining with other prostaglandin analogue eye drops, since this is not generally recommended.

Very common side effects

• Conjunctival hyperemia (eye redness) - the most common reaction, occurring in 30-50% of patients

Common side effects

• Iritis (eye inflammation)
• Dry eye
• Visual field defects
• Eye discomfort or stinging on instillation

Notable, expected changes with use (discuss with your doctor if concerning)

• Increased brown pigmentation of the iris: occurs gradually, may not be noticeable for months to years, and is likely to be permanent even after stopping the medicine; treatment can generally continue in patients who develop this, with regular eye examinations.
• Eyelid skin darkening: may be reversible after stopping the medicine.
• Eyelash and vellus hair changes: increased length, thickness, and number of lashes in the treated eye; usually reversible upon discontinuation.

Serious side effects (seek medical attention)

• Macular oedema (including cystoid macular oedema): new vision changes should be reported promptly; use with caution in patients who are aphakic, pseudophakic with a torn posterior lens capsule, or have other risk factors for this condition.
• Bacterial keratitis has been reported with contaminated multi-dose ophthalmic containers, particularly in patients with an already-compromised corneal surface; follow proper technique to avoid contaminating the dropper tip.
• Intraocular inflammation may worsen in patients with active uveitis; use with caution in this population.

Pregnancy

There are limited data on Avost 0.004% use in human pregnancy; use during pregnancy should only occur if a doctor determines the potential benefit outweighs any potential risk.

Breastfeeding

It is not known whether Avost 0.004% passes into human milk in clinically significant amounts; use during breastfeeding should be discussed with a healthcare professional.

• Iris pigmentation change: counsel patients before starting that Avost 0.004% can permanently increase brown pigmentation in the iris; this change occurs gradually and does not typically affect vision, but should be discussed and monitored at follow-up visits.
• Not evaluated for angle-closure, inflammatory, or neovascular glaucoma - use is specifically for open-angle glaucoma and ocular hypertension.
• Macular oedema risk: use with caution in aphakic or pseudophakic patients with risk factors for this condition.
• Active intraocular inflammation (uveitis): use with caution, since Avost 0.004% may exacerbate inflammation.
• Remove contact lenses before instillation, given the benzalkonium chloride preservative, and reinsert 15 minutes later.
• Do not exceed the once-daily dosing schedule, since more frequent use may reduce the intraocular pressure-lowering effect.

Topical ophthalmic overdose is unlikely to cause significant systemic effects with normal use, though excessive or more frequent use than directed does not improve effectiveness and may increase local irritation. If accidentally ingested, contact a doctor or pharmacist for advice. Discontinue use and seek medical attention if excessive eye irritation or unexpected symptoms occur.

Store at room temperature, protected from light, as directed on the product label; do not freeze. Keep the bottle tightly closed when not in use.

• Children under 16 years: Use is not recommended, given potential safety concerns related to increased pigmentation with long-term chronic use in this age group.
• Elderly: No specific dose adjustment is generally required.
• Patients with darker eye colour or mixed-colour irises: May be more likely to notice a gradual increase in brown pigmentation with treatment.

Avost 0.004% is used as ongoing, long-term therapy for glaucoma or ocular hypertension, for as long as it is needed to control intraocular pressure, with regular eye examinations to monitor effectiveness, iris pigmentation, and other treatment-related changes, as directed by the treating ophthalmologist.

Drug Class: Prostaglandin F2-alpha analogue

Avost 0.004%'s active metabolite binds to prostaglandin F receptors in the eye, increasing the outflow of aqueous humour (the fluid inside the eye) through the uveoscleral pathway, an alternative drainage route to the eye's main outflow channel. By increasing this outflow, Avost 0.004% reduces the amount of fluid inside the eye, lowering intraocular pressure and reducing the risk of optic nerve damage associated with elevated eye pressure in glaucoma and ocular hypertension.

Use of Avost 0.004% in children below the age of 16 years is not recommended, because of potential safety concerns related to increased pigmentation following long-term, chronic use in this age group.