What to Know About Cromolyn Sodium

Table of Contents
View All
Table of Contents

Cromolyn sodium is an inhaled asthma controller used for the prevention of asthma symptoms. As a mast cell stabilizer, cromolyn sodium inhibits the over-active inflammatory process that contributes to asthma symptoms—namely, the release of histamine and other immune proteins that trigger asthma. Cromolyn sodium also reduces the incidence of bronchospasm (sudden narrowing of the airways).

There are several formulations of cromolyn sodium used for various indications. Cromolyn sodium for the treatment of asthma is available as a generic, prescription nebulizer solution and as an over-the-counter (OTC) inhaler under the brand name NasalCrom.

Nebulizer treatment

Getty Images/yulkapopkova


Cromolyn sodium is indicated for the maintenance treatment of asthma for adults and children over age 2. This medication is used on a daily schedule and it can also be used before exposure to allergens or other asthma triggers (like exercise).

Cromolyn sodium is not used to relieve an ongoing asthma attack or to reduce ongoing asthma symptoms. In addition, cromolyn sodium is generally reserved for treating only mild to moderate asthma.

Your healthcare provider might prescribe or recommend a preventive medication if your asthma symptoms occur repeatedly and require frequent treatment with an asthma rescue medication.

Cromolyn sodium can help reduce the occurrence of:

There are a number of asthma controller medications, and your healthcare provider will select the right one for you based on your symptoms and risk of side effects. Cromolyn sodium tends to produce fewer side effects than inhaled corticosteroids, a common asthma controller, but it may also be less effective.

Cromolyn sodium has a valuable role in preventing the effects of exercise-induced asthma when it is used within an hour before symptoms occur, but not after asthma symptoms begin.

In addition to asthma, inhaled cromolyn sodium is also indicated for the treatment of allergic rhinitis.

An ophthalmic solution—Crolom, Cromoptic, and Opticrom—is used for treating certain inflammatory eye conditions. An oral liquid form, Gastrocrom, is used for treating systemic mastocytosis, an inflammatory condition.

It is not commonly used off-label.

Before Taking

If you have had an allergic reaction associated with cromolyn sodium, it is recommended that you don't use it or that you use it with caution according to your healthcare provider's instructions.

Talk to your healthcare provider about all medications, supplements, and vitamins that you currently take. While some drugs pose minor interaction risks, others may outright contraindicate use or prompt careful consideration as to whether the pros of treatment outweigh the cons in your case.

Precautions and Contraindications

This medication may pose a risk for children under age 2, pregnant mothers, and babies of mothers who are nursing.

You should not use this treatment if you have severe heart disease or arrhythmia (irregular heart rhythm).


Your healthcare provider will recommend the appropriate daily scheduled doses of either the inhaler or nebulizer solution forms of cromolyn sodium.

You may also receive instructions so that you will know when and how to use your cromolyn sodium treatment to prevent symptoms of exercise-induced asthma or allergen-induced asthma when you anticipate these effects in advance.

You should follow your healthcare provider's instructions regarding a regular dosing regimen and as-needed preventative treatments, as appropriate.

Drug Form mg/Dose Maintenance Dose In Anticipation of Symptoms
Nebulizer solution 20 mg per 2 mL ampule

20 mg of nebulized solution four times per day

You can take 20 mg of medication no more than one hour before your anticipated exposure to your asthma trigger, if needed.
NasalCrom Inhaler 5.2 mg per spray One spray in each nostril three to four times a day; max. six times a day if needed

You can use one spray in each nostril within an hour of anticipated asthma symptoms if instructed to use it this way by your doctor.


The short-term preventive effect is expected to last for approximately one to two hours.

Keep in mind that the recommended dose of cromolyn sodium for asthma is different than for allergies. Cromolyn sodium should only be used for 12 weeks when used for allergies, but it is often recommended for a longer duration when used for asthma. Follow your prescriber's instructions.


If you have kidney disease or liver disease, your healthcare provider will recommend that you use a lower than recommended dose of cromolyn sodium. The reduction in dose will be based on the severity of your liver or kidney disease. The more impaired your liver or kidney function, the lower your recommended dose of cromolyn sodium.

How to Take and Store

It is important that you learn how to take your inhaler or use your nebulizer correctly. It's a good idea to use your inhaled treatment with medical supervision for the first time so you can ensure that you are fully inhaling the medication for optimal effects.

A nebulizer solution is prepared by breaking the ampule and placing the powder that's inside the ampule into your nebulizer with water. Your device will heat the solution and then sent the mist that's produced through a tube so you can inhale your medication.

Cromolyn sodium should be stored away from light at room temperature (between 68 and 77 degrees F).

Discard any remaining expired medication based on your pharmacist's instructions, or take it to your pharmacy for proper disposal.

Side Effects

While using cromolyn sodium is generally safe, there is a risk of a range of side effects.


Cromolyn sodium causes a number of mild side effects. You might experience them right when you start using the drug, or they can develop after you've used the treatment for months. Be sure to tell your healthcare provider if these effects are very bothersome for you.

Common side effects include:

  • Bad taste in your mouth
  • Cough
  • Itching
  • Sore throat
  • Headache
  • Sneezing or stuffy nose


Serious side effects are rare with cromolyn sodium, but they can occur and may include:

Be sure to contact your healthcare provider or seek urgent medical attention if you begin to experience serious side effects. Don't wait to see if a problem subsides on its own.

Warnings and Interactions

Using cromolyn sodium when you are currently experiencing asthma symptoms may make your asthma symptoms worse. Be sure that you always have a rescue inhaler handy.

If you have had asthma for over 10 years, you might have used other forms of inhaled cromolyn sodium. Cromolyn sodium had been available under the brand name Intal as an asthma inhaler and a nebulizer solution.

The manufacturer stopped making Intal due to regulations regarding the safety of three chlorofluorocarbon (CFC), a material that was commonly used in many asthma inhalers as a propellant.

Cromolyn sodium is considered safe, but the formulations that used CFCs to help with the inhalation process are not permitted due to environmental concerns.

Cromolyn sodium is not known to have any drug interactions.

A Word From Verywell

Cromolyn sodium is an inhaled mast cell stabilizer used for preventing symptoms of asthma for children and adults age 2 and older. It is considered safe, will minimal warnings and side effects. However, cromolyn sodium is not typically used for treating severe asthma. If your symptoms are not well-controlled while using this drug, speak to your healthcare provider. It is possible that your asthma has progressed.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Mombeini T, Zahedpoure-anaraki MR, Dehpour AR. Effects of Sodium Cromoglycate on Iranian Asthmatic Subjects Without Exposure to any Bronchoconstrictor agent. Iran J Pharm Res. 11(2):549-57.

  2. Asthma and Allergy Foundation of America. Cromolyn sodium.

  3. Netzer NC, Küpper T, Voss HW, Eliasson AH. The actual role of sodium cromoglycate in the treatment of asthma--a critical review. Sleep Breath. 2012;16(4):1027-32.doi:10.1007/s11325-011-0639-1

  4. Prescribers' Digital Reference. Cromolyn sodium drug summary.

  5. Food and Drug Administration. Intal inhaler label.

  6. American Academy of Family Physicians. FDA Issues Final Rule on CFC-based Inhalers.

By Pat Bass, MD
Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians.