Mastguard4%

Mastguard is a mast cell stabilizer used as a preventive (prophylactic) topical treatment for allergic eye and nose conditions. It is not intended for rapid relief of acute symptoms.

Established/approved uses

• Ophthalmic solution: Prevention and treatment of vernal keratoconjunctivitis, vernal conjunctivitis, and vernal keratitis; also used for allergic conjunctivitis.
• Nasal solution/spray: Prevention and relief of symptoms of seasonal and perennial allergic rhinitis, including sneezing, nasal itching, rhinorrhea (runny nose), and nasal congestion caused by exposure to allergens.

Notes on evidence

Mastguard works best when started before allergen exposure (e.g., before a known pollen season) and used regularly; it is less effective once symptoms are already established. It is not a substitute for antihistamines or corticosteroids in acute or severe allergic symptoms and may be used as an adjunct to these therapies when appropriate.

Each formulation of Sodium Cromoglicate [4%] contains sodium cromoglicate (also known as cromolyn sodium/disodium cromoglycate) as the active ingredient at a strength of 4% w/v (40 mg/mL), formulated as either a sterile ophthalmic solution (eye drops) or an aqueous nasal spray solution, depending on the product. Excipients vary by manufacturer and may include preservatives, buffering agents, and purified water.

Mastguard is a topical anti-allergic medicine belonging to the mast cell stabilizer class. It is available as a 4% ophthalmic solution for allergic eye conditions and/or as a 4% nasal solution for allergic rhinitis. Unlike antihistamines, it does not block histamine receptors; instead it prevents the release of histamine and other inflammatory mediators from mast cells before they are triggered by an allergen.

Because of this mechanism, Mastguard is used mainly as a preventive medicine and must be used consistently, often several times a day, for its full benefit to develop.

Mastguard belongs to the therapeutic class of mast cell stabilizers (anti-allergic agents), used topically for ophthalmic and nasal allergic conditions.

Sodium Cromoglicate [4%] (sodium cromoglicate) stabilizes the membrane of sensitized mast cells, preventing degranulation that occurs when an allergen cross-links IgE antibodies bound to the mast cell surface. This action inhibits the release of histamine, leukotrienes, and other inflammatory mediators that cause the symptoms of allergic conjunctivitis and allergic rhinitis.

Sodium Cromoglicate [4%] has no significant intrinsic anti-histaminic, anti-inflammatory (corticosteroid-like), or vasoconstrictor activity. Its effect is preventive rather than symptomatic, and onset of clinically meaningful benefit typically takes several days to a few weeks of regular use.

Pharmacokinetics: Only a small fraction of a topically applied ophthalmic or nasal dose of Sodium Cromoglicate [4%] is absorbed systemically. Absorbed drug is not metabolized and is excreted largely unchanged in urine and bile in roughly equal proportions.

• For ophthalmic use: wash hands before use, tilt the head back, gently pull down the lower eyelid, instill the drop of Mastguard into the pocket formed, and avoid touching the dropper tip to the eye or any surface.
• For nasal use: clear the nostrils gently before use, insert the nozzle into one nostril while closing the other, and spray Mastguard while inhaling gently through the nose.
• Mastguard should be used at evenly spaced intervals through the day as prescribed, not only when symptoms occur, since it works by preventing allergic reactions rather than relieving them once they start.
• If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next dose.

Clinically significant drug interactions with Mastguard are uncommon because of its minimal systemic absorption and lack of enzymatic metabolism. No well-established, clinically significant interactions with other systemic medicines have been established for Mastguard.

Mastguard may be used concurrently with other topical ophthalmic or nasal medicines (such as antihistamines or corticosteroids) when prescribed together, generally without an adjustment in dosing; however, if multiple topical products are used in the same eye or nostril, they should be administered a few minutes apart, and a physician or pharmacist should be consulted about the correct sequence.

Mastguard is generally very well tolerated because of its minimal systemic absorption. Reported side effects are mostly local and transient.

• Ophthalmic use: Transient stinging, burning, or discomfort on instillation; temporary blurred vision immediately after application; eye irritation, dryness, or watering; puffy eyes.
• Nasal use: Transient nasal irritation, sneezing, burning, or stinging in the nose; unpleasant taste; nosebleeds; headache.
• Uncommon/rare: Hypersensitivity reactions (rash, urticaria, angioedema); rarely, bronchospasm or cough with nasal use.

Patients should contact their physician if irritation is severe or persistent, or if signs of an allergic reaction occur.

Systemic absorption of Mastguard after ophthalmic or nasal administration is minimal. Although this supports a relatively favorable safety profile compared with systemically absorbed drugs, Mastguard should be used during pregnancy only if clearly needed, and the potential benefit is judged by the prescribing physician to justify the potential risk to the fetus. A physician should always be consulted before use in pregnancy.

It is not known whether clinically significant amounts of Mastguard pass into breast milk after topical ophthalmic or nasal use; because systemic absorption is low, risk to a nursing infant is considered minimal, but a physician should be consulted before use while breastfeeding.

• Mastguard is a preventive (prophylactic) medicine, not a fast-acting reliever; it does not provide immediate relief of acute allergic symptoms and should not be relied upon during an acute severe allergic attack.
• Onset of full benefit may take several days to a few weeks of regular, uninterrupted use; patients should not stop the medicine as soon as symptoms improve without medical advice, and should continue it throughout the period of allergen exposure.
• Mild, transient stinging or irritation immediately after instillation is common and usually does not require stopping treatment; see Side Effects for details.
• Mastguard is not a substitute for antihistamines or corticosteroids when these are required for acute or severe allergic symptoms; it may be used together with such treatments on medical advice.
• For ophthalmic use, contact lenses should generally not be worn during a course of treatment unless a physician advises otherwise, and users of preserved formulations should follow product-specific advice about lens wear.
• If symptoms worsen, do not improve after a reasonable trial period, or new symptoms (such as severe eye pain, vision changes, or facial swelling) develop, medical advice should be sought promptly.

Because of the minimal systemic absorption of Mastguard with normal ophthalmic or nasal use, the risk of serious toxicity from overdose is low. Excessive or accidental oral ingestion of the solution, or significant overuse, is unlikely to cause severe harm but may cause increased local irritation or gastrointestinal upset.

If a significantly larger than recommended amount of Mastguard is used or accidentally swallowed, or if the person shows any unusual symptoms, seek immediate medical attention or contact a poison control center/emergency services rather than attempting home treatment.

Store at room temperature (below 30°C), away from light and moisture. Do not freeze. Keep the container tightly closed when not in use, and discard any unused solution after the period stated on the product label once opened. Keep out of reach of children.

Elderly: No specific dose adjustment is generally required for Mastguard in elderly patients; it may be used as in younger adults, subject to physician assessment.

Renal/hepatic impairment: No well-established dose adjustment is required for Mastguard in renal or hepatic impairment given its minimal systemic absorption and lack of hepatic metabolism, but a physician should still be consulted in patients with significant organ impairment.

Pediatric and pregnancy/lactation populations: See Pediatric Uses and Pregnancy and Lactation sections for details specific to Mastguard.

Mastguard is typically used for the duration of expected allergen exposure (for example, throughout a pollen season for seasonal allergic rhinitis or conjunctivitis, or continuously for perennial/year-round allergic symptoms). Treatment is usually started shortly before anticipated exposure and continued without interruption for it to remain effective. The exact duration should be individualized by the prescribing physician based on symptom pattern and response.

Sodium Cromoglicate [4%] belongs to the drug class of mast cell stabilizers (also referred to as cromones), a category of anti-allergic agents distinct from antihistamines, corticosteroids, and decongestants.

Sodium Cromoglicate [4%] acts by stabilizing sensitized mast cell membranes, preventing the calcium-dependent degranulation that normally follows allergen-triggered cross-linking of IgE on the mast cell surface. This blocks the release of histamine, leukotrienes, and other mediators responsible for the itching, redness, swelling, sneezing, and mucus production seen in allergic conjunctivitis and allergic rhinitis. Because it works upstream of mediator release rather than blocking their effects, Sodium Cromoglicate [4%] is preventive rather than symptom-relieving in action.

B

Use of Mastguard in children should follow approved age-based labeling for the specific formulation:

• Ophthalmic solution: Generally approved for use in children above the age specified on the product label (commonly above 4 years); safety and efficacy in younger children have not been well established and should only be used under close physician supervision if prescribed.
• Nasal solution/spray: Generally approved for use in children above the age specified on the product label (commonly above 2 years); safety and efficacy below this age have not been established.

Dosing in eligible children follows the same schedule as adults for the corresponding formulation unless otherwise directed by a physician; see Dosage and Administration.