CROMOLYN SODIUM

Clinical safety rating: safe

Animal studies have demonstrated safety

How it works

Stabilizes mast cell membranes, inhibiting release of histamine and other mediators of inflammation.

What the body does with it

Metabolism	Not metabolized; excreted unchanged in urine and bile.
Excretion	Primarily excreted unchanged in bile and feces (approximately 98% after oral administration); renal excretion is minimal (<1% unchanged in urine). After inhalation, a small amount is absorbed systemically and similarly excreted via bile/feces.
Half-life	Terminal elimination half-life is approximately 1-1.5 hours for the absorbed fraction; the short half-life necessitates frequent dosing (e.g., 4 times daily) for sustained clinical effect.
Protein binding	Approximately 65-75% bound to plasma proteins, primarily albumin.
Volume of Distribution	Approximately 0.3 L/kg for the absorbed fraction; indicates distribution primarily in extracellular fluid with limited tissue penetration.
Bioavailability	Inhalation: Very low systemic bioavailability (<1% due to poor absorption from lungs). Oral: Extremely low (<1%) due to poor gastrointestinal absorption; the non-absorbed fraction acts locally in the gut. Ophthalmic: Minimal systemic absorption (<0.5%).
Onset of Action	Inhalation: Onset of prophylactic effect occurs within 2-6 weeks of regular use; immediate bronchodilation is not observed. Oral (mastocytosis): Onset of symptom relief typically within 2-4 weeks. Ophthalmic: Onset of symptom relief within 2-4 days. No immediate effect for acute attacks.
Duration of Action	Inhalation: Duration of prophylactic effect lasts 4-6 hours after each dose; requires consistent dosing every 4-6 hours. Ophthalmic: Duration of symptomatic relief is 4-6 hours per dose. Oral: Duration varies; sustained use for 2-4 weeks needed for maximal benefit.

Classification & Brands

Dosing & administration

For bronchial asthma: 20 mg (2 capsules) orally 4 times daily, administered 1 hour before meals and at bedtime. For allergic rhinitis: 1 spray (5.2 mg) in each nostril 3-6 times daily. For mastocytosis: 200 mg orally 4 times daily.

Dosage form	CONCENTRATE
Renal impairment	No specific dose adjustment recommendations available; use with caution in severe renal impairment. Cromolyn sodium is primarily excreted unchanged in urine, but limited data preclude precise GFR-based modifications.
Liver impairment	No specific dose adjustment guidelines based on Child-Pugh score; pharmacokinetics not significantly altered in hepatic impairment.
Pediatric use	For asthma (children ≥2 years): 20 mg orally 4 times daily. For allergic rhinitis (children ≥6 years): 1 spray/nostril 3-6 times daily. For mastocytosis (children 2-12 years): 100 mg orally 4 times daily.
Geriatric use	Use with caution due to potential age-related decline in renal function. No specific dose adjustment, but monitor renal function and consider starting at lower end of dosing range.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

No significant drug interactions Not for acute treatment of an asthma attack.

Breastfeeding	Excretion into breast milk unknown; minimal systemic absorption suggests low risk. M/P ratio not reported. Caution with high-dose oral use, but inhaled/ocular routes considered safe.
Teratogenic Risk	Pregnancy category B. No evidence of teratogenicity in animal studies. No well-controlled human studies; however, extensive clinical experience suggests low risk across all trimesters. Topical ocular or inhaled use minimizes systemic absorption.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Common Effects	asthma
Serious Effects

Absolute Contraindications

Hypersensitivity to cromolyn sodium or any component of the formulation.

Clinical Precautions

Precautions

May cause bronchospasm, cough, or wheezing upon inhalation; discontinued if eosinophilic pneumonia occurs.

Clinical Tips & Counseling

Drug interactions

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