Pemast0.1%

Pemast ophthalmic solution is indicated for the prevention of itching associated with allergic conjunctivitis.

• Established/FDA-approved use: Prevention of ocular itching due to allergic conjunctivitis.
• Not indicated for: Treatment of contact lens–related ocular irritation.

The full benefit of Pemast may take up to four weeks of regular use to develop; it is therefore best used prophylactically, before or during the allergy season, rather than for acute symptom relief.

Each mL of Pemirolast Potassium ophthalmic solution contains pemirolast potassium 1 mg (0.1% w/v) as the active ingredient, together with benzalkonium chloride as a preservative and other inactive ingredients (e.g., sodium chloride, edetate disodium, purified water) to form a sterile, isotonic ophthalmic solution.

Pemast is a topical ophthalmic mast cell stabilizer used to prevent the eye itching that occurs with allergic conjunctivitis (allergic "pink eye"). It is supplied as a sterile 0.1% ophthalmic solution intended for instillation into the eye.

Pemast belongs to the therapeutic class of ophthalmic anti-allergic agents, specifically mast cell stabilizers used for ocular allergy.

Pemirolast Potassium is a mast cell stabilizer that inhibits the antigen-induced release of histamine and other mediators of the immediate hypersensitivity reaction (e.g., leukotrienes) from mast cells. By preventing mast cell degranulation, Pemirolast Potassium reduces the release of histamine, which is primarily responsible for the itching seen in allergic conjunctivitis.

Following ocular administration, systemic absorption of Pemirolast Potassium is minimal.

For topical ophthalmic use only. Tilt the head back, pull down the lower eyelid to form a pocket, and instill the drop(s) of Pemast without letting the dropper tip touch the eye or any other surface. Wash hands before and after use.

Contact lenses should be removed prior to instillation of Pemast and may be reinserted 10 minutes after administration. Pemast should not be used to treat contact lens–related irritation.

No clinically significant drug interactions have been well established for Pemast ophthalmic solution, reflecting its minimal systemic absorption after topical ocular use.

As a general precaution, if other topical ophthalmic medications are used concurrently with Pemast, they should be administered at least 5 minutes apart to prevent one product from diluting or washing out the other.

The most commonly reported adverse effects with Pemast ophthalmic solution include:

• Headache
• Rhinitis
• Cough
• Mild, transient burning or stinging sensation upon instillation
• Eye pain or irritation

Less commonly, dry eye, foreign body sensation, and conjunctival injection have been reported. If persistent eye pain, vision changes, redness, or signs of infection occur while using Pemast, discontinue use and consult a physician.

Systemic absorption of Pemast after ophthalmic administration is minimal; however, adequate and well-controlled studies in pregnant women are lacking. Pemast should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; consult a physician before use.

It is not known whether Pemast is excreted in human milk. Caution should be exercised, and a physician should be consulted before using Pemast while breastfeeding.

Pemast is for topical ophthalmic use only and must not be injected or taken orally.

• Pemast is not indicated for the treatment of contact lens–related ocular irritation.
• Contact lenses should be removed before instilling Pemast and may be reinserted 10 minutes after administration.
• The container tip should not touch the eye or any other surface, to avoid contaminating the solution.
• If eye pain, changes in vision, redness, or itching worsens or persists, or if a new problem occurs, discontinue Pemast and consult a physician.
• See Side Effects for common reactions and Pregnancy and Lactation for use in pregnant or breastfeeding women.

Overdose with topical ophthalmic Pemast is unlikely to cause significant systemic toxicity due to its minimal systemic absorption. If Pemast is accidentally ingested, or if excessive amounts are instilled and irritation or other symptoms occur, seek immediate medical attention or contact a poison control center; supportive care should be provided as needed.

Store at room temperature (below 30°C), away from light and moisture. Keep the bottle tightly closed and out of reach of children. Do not use after the expiry date printed on the label.

Renal/Hepatic impairment: No specific dose adjustment of Pemast is established or generally required, given its minimal systemic absorption via the ophthalmic route.

Elderly: No overall differences in safety or effectiveness of Pemast have been observed between elderly and younger patients.

Pediatric: Safety and efficacy of Pemast have been established in children 3 years of age and older; safety and efficacy in children under 3 years have not been established. See Pediatric Uses.

Pregnancy and lactation: See Pregnancy and Lactation.

Pemast is generally used throughout the allergy season, for as long as exposure to the allergen continues, since its full benefit may take up to four weeks of regular use to become apparent. Treatment duration should be guided by a physician based on symptom control and the anticipated duration of allergen exposure.

Mast cell stabilizer; ophthalmic anti-allergic agent.

Pemirolast Potassium stabilizes mast cell membranes and inhibits the antigen-induced release of histamine and other inflammatory mediators (such as leukotrienes) from sensitized mast cells in the conjunctiva. By preventing this mediator release, Pemirolast Potassium reduces the histamine-driven itching characteristic of allergic conjunctivitis, without acting as an antihistamine itself.

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The safety and effectiveness of Pemast ophthalmic solution have been established in pediatric patients 3 years of age and older, using the same dosage as adults (1–2 drops in the affected eye(s) four times daily). Safety and efficacy of Pemast in children younger than 3 years have not been established.