The Asthma Center

Cromolyn Sodium

Cromolyn sodium (Intal®) is a unique preventive medication for asthma. It prevents the mast cells in the airways from releasing their chemical mediators that cause asthmatic symptoms and inflammation.

Cromolyn is not a bronchodilator. It will not provide quick relief if you are actively wheezing.

Cromolyn can prevent asthma caused by inhaled allergens. Cromolyn has also been shown to lower the overall irritability of the airways, and thus you may become less sensitive to several stimuli that ordinarily provoke your asthmatic symptoms.


Cromolyn is best used as a continuous treatment. It is inhaled as a metered-dose inhaler 2 - 4 times per day, even when you have few or no symptoms. Cromolyn is truly a preventive medication. This medication often takes weeks or even months to demonstrate its benefits.

Cromolyn also comes as a solution for nebulization. Nebulization of cromolyn solution through a mask or mouthpiece has been very effective in young children with chronic or frequent episodes of asthma. Cromolyn also has been very effective in controlling the chronic cough of asthma.

Cromolyn can be inhaled 15 - 30 minutes prior to exposure to an environment containing a known allergen. For example, if you are cat-sensitive and visit a friend who has a cat, prior use of cromolyn may allow you to tolerate such exposure. Of course, it would always be wiser to avoid exposure to allergic factors, but cromolyn gives you some control when it cannot be avoided.

If you are exposed to allergens at work, you may receive great benefit from cromolyn. In addition, cromolyn has been found to be effective in blocking exercise-induced asthma when taken prior to participating in sports. In this situation, it may be an alternative or supplement to inhaled ß2 stimulants (e.g. albuterol) or theophylline preparations.

Cromolyn sodium is not always effective. However, when it works, it is one of the best medications, as it completely blocks inflammation at the highest possible level, while also having the lowest incidence of side effects of any asthma medications.

Risks and Precautions

Unlike many other asthma medications, cromolyn sodium rarely causes side effects. Occasionally you may complain of coughing, sore throat, itchy rash, flushing, gastrointestinal upset and/or headache