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Cromolyn (EENT)

Class: Antiallergic Agents
VA Class: RE100
CAS Number: 15826-37-6
Brands: Crolom, Nasalcrom

Medically reviewed by on Jun 21, 2021. Written by ASHP.


Mast-cell stabilizer.

Uses for Cromolyn (EENT)

Allergic Rhinitis

Self-medication for the symptomatic prevention and treatment of seasonal or perennial allergic rhinitis. Provides symptomatic relief of rhinorrhea, nasal congestion, sneezing, and postnasal drip.

Should not use as self-medication for the treatment of sinus infection, asthma, or cold symptoms.

Allergic Ocular Disorders

Symptomatic treatment of certain allergic ocular disorders (e.g., vernal keratoconjunctivitis, vernal conjunctivitis, vernal keratitis).

Has been used for the treatment of giant papillary conjunctivitis.

Cromolyn (EENT) Dosage and Administration


  • For patients with seasonal or perennial rhinitis, continue therapy throughout the period of allergen exposure (e.g., until the pollen season is over or contact with allergen has ceased).

  • If exposure to allergens cannot be predicted, initiate therapy at the first sign of nasal symptoms.

  • Should not use other ocular agents with ophthalmic solution unless directed by a clinician. However, may use corticosteroids with ophthalmic solution.


Administer intranasally or topically to the eye.

Administer at regular intervals.

Intranasal Administration

Parents or care providers must supervise use by young children. In very young children, an adult should administer nasal solution. Use care when inserting the nozzle into the nose to avoid injury.

Prior to administration, clear nasal passages by blowing the nose; administration of a topical nasal decongestant may be necessary. Inhale through the nose during administration.

For maximum therapeutic effect, initiate therapy before (e.g., ≤1–2 weeks before) and continue at regular intervals during the period of allergen exposure.

Ophthalmic Administration

Applied topically to the eye as an ophthalmic solution just inside the lower eyelid; patients should avoid applying the solution directly on the cornea.

To avoid contamination of dropper tip and solution, avoid touching the tip of the dispensing dropper or container to the eye, fingers, or any other surface.


Available as cromolyn sodium.

Nasal pump delivers 5.2 mg of cromolyn sodium per metered spray.

One drop of cromolyn sodium ophthalmic solution contains approximately 1.6 mg of cromolyn sodium.

Pediatric Patients

Allergic Rhinitis

Children ≥2 years of age: 1 spray (5.2 mg) in each nostril 3 or 4 times daily given at regular intervals (morning, noon, dinner, bedtime) for ≤12 weeks. When necessary, may be used up to 6 times daily.

Allergic Ocular Disorders

Children ≥4 years of age: 1 or 2 drops in each eye 4–6 times daily at regular intervals.

Do not exceed recommended frequency of administration.


Allergic Rhinitis

1 spray (5.2 mg) in each nostril 3 or 4 times daily (morning, noon, dinner, bedtime) for ≤12 weeks. When necessary, may be used up to 6 times daily.

Allergic Ocular Disorders

1 or 2 drops in each eye 4–6 times daily at regular intervals.

Cautions for Cromolyn (EENT)


  • Known hypersensitivity to cromolyn sodium or any ingredient in the formulations.



General Precautions

Ocular Effects

Ophthalmic solution: Transient stinging or burning sensation may occur.

Respiratory Effects

Nasal solution: Transient nasal stinging and/or sneezing may occur immediately. Discontinue drug if nasal irritation occurs.

Specific Populations


Category B.


Not known whether cromolyn is distributed into milk. Use ophthalmic solution with caution. With nasal spray, consult a clinician prior to use.

Pediatric Use

Safety and efficacy of cromolyn sodium given as the nasal solution or ophthalmic solution not established in children <2 or <4 years of age, respectively.

Geriatric Use

Ophthalmic solution: No differences in safety or efficacy relative to younger adults.

Common Adverse Effects

Nasal solution: Nasal burning and stinging, nasal irritation, sneezing.

Ophthalmic solution: Transient ocular stinging or burning upon instillation.

Cromolyn (EENT) Pharmacokinetics



Approximately <7 or 0.03% absorbed following an intranasal dose or an ophthalmic dose, respectively.


Nasal solution: Improvement may take several days; best effect not seen for 1–2 weeks.

Ophthalmic solution: Improvement usually noted in a few days; treatment for up to 6 weeks sometimes needed to see improvement.



Does not cross most biologic membranes well.

Minimally crosses the placenta (<0.1%) and minimally distributed into milk (<0.001% of a dose) in animals.



81 minutes.




Nasal Solution

20–25°C; protect from light.


Ophthalmic Solution

20–25°C or 15–30°C, depending on manufacturer; protect from light. Store in original carton.


  • Acts mainly through a local effect on the nasal mucosa or eyes.

  • Inhibits degranulation of sensitized mast cells that occurs after exposure to specific antigens. Inhibits release of mediators of type I allergic reactions, including histamine and cysteinyl leukotrienes (slow-reacting substance of anaphylaxis [SRS-A]) from sensitized mast cells. Inhibits phospholipase A-induced mast cell degranulation and subsequent release of chemical mediators in vitro.

  • No direct antihistamine, anticholinergic, antiserotonin, anti-inflammatory, vasoconstrictor, or corticosteroid-like properties.

Advice to Patients

  • Importance of providing patient a copy of manufacturer’s patient information.

  • Importance of clinicians instructing patients about proper use, including proper administration of the particular dosage form employed.

  • With nasal solution, importance of informing a clinician of symptoms such as fever, discolored nasal discharge, sinus pain, or wheezing prior to use.

  • Importance of administration of drug at regular intervals.

  • Importance of avoiding exposure to allergens.

  • Importance of advising patients with seasonal or perennial allergic rhinitis to begin therapy before (e.g., ≤1–2 weeks before), and to continue therapy at regular intervals during, the period of allergen exposure.

  • With intranasal cromolyn, importance of advising patients with allergic rhinitis to discontinue therapy and consult a clinician if symptoms worsen, new symptoms occur, symptoms do not begin to improve within 2 weeks of treatment initiation, or if treatment is required for longer than >12 weeks.

  • Importance of discontinuing drug and contacting a clinician if shortness of breath, wheezing, hives or swelling of the mouth or throat, or chest tightness occurs.

  • Importance of not wearing contact lenses during treatment with cromolyn ophthalmic solution.

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Cromolyn Sodium


Dosage Forms


Brand Names




5.2 mg/metered spray*

Cromolyn Sodium Nasal Spray (with benzalkonium chloride 0.01% and edetate disodium 0.1%)

Actavis, Bausch & Lomb, Perrigo

Nasalcrom (with benzalkonium chloride 0.01% and edetate disodium 0.1%)





Crolom (with benzalkonium chloride 0.01% and edetate disodium 0.1%)

Bausch & Lomb

Cromolyn Sodium Ophthalmic Solution (with benzalkonium chloride 0.01% and edetate disodium 0.1%)

Akorn, Alcon, King, Novex, Pacific Pharma

AHFS DI Essentials™. © Copyright 2022, Selected Revisions July 1, 2007. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

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