What it's for (Indications)
- This combination ophthalmic solution, containing sodium cromoglycate and tetrahydrozoline, is indicated for the symptomatic relief of allergic conjunctivitis.
- Sodium cromoglycate acts as a mast cell stabilizer, preventing the release of histamine and other inflammatory mediators responsible for allergic reactions.
- Tetrahydrozoline functions as a topical ocular decongestant, primarily reducing conjunctival hyperemia (redness) by vasoconstriction of small arterioles in the eye.
- This dual action aims to alleviate both the underlying allergic inflammatory process and the associated uncomfortable symptoms of eye redness, itching, and irritation.
- It is typically prescribed for seasonal or perennial allergic conjunctivitis when both the allergic response and significant ocular redness are present.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | The typical adult and pediatric (aged 6 years and older) dosage for sodium cromoglycate 2% / tetrahydrozoline 0.05% ophthalmic solution is one or two drops instilled into the affected eye(s) four times daily, or as directed by a healthcare professional. For optimal therapeutic effect, especially for the mast cell stabilizing action of sodium cromoglycate, consistent use even during asymptomatic periods may be recommended, particularly prior to anticipated allergen exposure. Dosage adjustments or cessation should only occur under the guidance of an ophthalmologist or physician due to potential rebound hyperemia with tetrahydrozoline upon abrupt discontinuation or overuse. Treatment duration should be limited for the tetrahydrozoline component to prevent chronic issues. |
Safety & Warnings
Common Side Effects
- Common side effects associated with this combination ophthalmic solution include transient stinging or burning upon instillation, ocular irritation, blurred vision, pupil dilation (mydriasis), and rebound conjunctival hyperemia, particularly with prolonged or excessive use of tetrahydrozoline.
- Other less common but possible local effects include punctate keratitis, eye pain, and lacrimation.
- Systemic absorption, though usually minimal with ophthalmic administration, can lead to systemic effects such as headache, nausea, sweating, tremor, weakness, and elevated blood pressure, especially in susceptible individuals or with overdose.
- Patients should be advised to discontinue use and consult a physician if severe or persistent adverse reactions occur, or if signs of systemic toxicity manifest.
Serious Warnings
- Black Box Warning: While there is no formal FDA-issued Black Box Warning specifically for ophthalmic solutions combining sodium cromoglycate and tetrahydrozoline, healthcare professionals and patients must be made aware of significant safety concerns, particularly related to the tetrahydrozoline component, which necessitate stringent precautions and monitoring. **Serious Warnings Regarding Tetrahydrozoline Overuse, Rebound Hyperemia, and Systemic Absorption:** Prolonged or excessive use of ophthalmic solutions containing tetrahydrozoline can lead to rebound conjunctival hyperemia, where the eye redness and irritation paradoxically worsen upon discontinuation or between doses, creating a cycle of dependency. This rebound effect can mask symptoms of serious underlying ocular conditions, delaying appropriate diagnosis and treatment, and potentially leading to chronic ocular surface issues. Furthermore, despite topical administration, systemic absorption of tetrahydrozoline can occur, especially with overuse, in young children, or in individuals with compromised ocular surface integrity. Systemic absorption may lead to significant cardiovascular and central nervous system effects, including severe hypertension, tachycardia, headache, sweating, tremor, weakness, and potential for severe adverse events such as cardiac arrhythmias, stroke, or central nervous system depression in susceptible populations. Cases of severe systemic poisoning, including profound bradycardia, hypotension, and central nervous system depression, particularly in young children due to accidental ingestion, have been reported with similar ophthalmic decongestants. Therefore, this product must be kept strictly out of reach of children. Patients should be advised to adhere strictly to recommended dosing regimens and duration of use (typically not exceeding 72 hours) to mitigate these risks. Discontinue use and seek immediate medical attention if symptoms persist, worsen, or if systemic effects are suspected.
- This medication is for ophthalmic use only and should not be swallowed.
- Patients should be advised about the potential for rebound conjunctival hyperemia and irritation if tetrahydrozoline-containing products are used excessively or for prolonged periods (typically beyond 72 hours), which can mask serious underlying eye conditions or lead to chronic irritation.
- While typically well-tolerated, systemic absorption of tetrahydrozoline can occur, potentially leading to cardiovascular effects like hypertension, tachycardia, or arrhythmias, especially in patients with pre-existing conditions (e.
- g.
- , cardiovascular disease, hyperthyroidism, diabetes) or those taking certain systemic medications (e.
- g.
- , MAO inhibitors).
- Patients with narrow-angle glaucoma should use with extreme caution due to the risk of inducing an acute attack.
- Contact lens wearers should remove lenses prior to instillation and wait at least 15 minutes before reinserting them to avoid absorption into the lens material.
- If symptoms worsen or persist beyond 72 hours, medical consultation is imperative as it may indicate a more serious ocular condition.
- Avoid contamination of the dropper tip by not touching it to any surface including the eye.
How it Works (Mechanism of Action)
Sodium cromoglycate exerts its therapeutic effect by stabilizing mast cell membranes, thereby inhibiting the degranulation of mast cells and the subsequent release of inflammatory mediators such as histamine, leukotrienes, and prostaglandins, which are central to allergic reactions. It does not possess intrinsic antihistaminic or vasoconstrictor activity. Its action is prophylactic, preventing the onset of allergic symptoms rather than reversing existing ones. Tetrahydrozoline hydrochloride is an alpha-adrenergic agonist that causes direct vasoconstriction of the conjunctival blood vessels, leading to a reduction in ocular redness. It achieves this by directly stimulating alpha-adrenergic receptors located in the arterioles of the conjunctiva. The combination thus provides both preventive anti-allergic action and symptomatic relief of associated ocular redness and irritation.
Commercial Brands (Alternatives)
No other brands found for this formula.