An allergic reaction occurs when the immune system mistakenly identifies a harmless substance as a dangerous intruder and begins to fight against it. This substance is known as an allergen. When your body reacts to it, a natural chemical called histamine is released. The histamine causes many uncomfortable symptoms, such as a runny nose, sneezing, and itchy eyes.

Histamine is produced by a type of immune system cell known as a mast cell. The mast cells play a critical role in defending the body from disease. They are the first cells that respond to the presence of foreign substances, such as allergens.

Some allergy-fighting drugs block the action of histamine after it’s released by mast cells. Cromolyn sodium works differently. It’s a so-called “mast cell stabilizer.” This means it stops mast cells from releasing histamine and other inflammatory chemicals in the first place. As a result, it helps prevent allergy symptoms. Cromolyn sodium is primarily used to prevent allergy-induced asthma attacks. For general environmental allergies, cromolyn sodium is now considered a second- or third-line treatment. Nasal corticosteroids and antihistamines are more commonly used for this purpose.

Cromolyn sodium originally derived from a healing herb called ammi visnaga. Among its other uses, ammi visnaga traditionally controlled kidney stone pain. Its ability to open the airways intrigued early researchers. They eventually identified the plant’s active ingredient: cromolyn sodium. Cromolyn sodium is known to prevent mast cells from triggering the immune response. This response causes unpleasant allergy symptoms. However, it’s uncertain exactly how this activity helps prevent asthma attacks.

Cromolyn sodium (Nasalcrom) comes as a solution that’s used with a special nasal applicator. The medication is inhaled through the nose and into the lungs. It must be inhaled three to six times per day to prevent allergy symptoms. The medication is more effective when it’s taken before an allergic reaction begins. It’s best to use it before being exposed to any potential allergens.

Make sure to speak with your doctor before using cromolyn sodium. It’s important that you know how to use the medication properly. You should always follow the directions on the package or prescription label carefully. Only use the medication exactly as directed. You should also take every recommended dose. This is because the medication is more effective when used continually. However, it can take up to four weeks for cromolyn sodium to reach its full effect. So you may not see an improvement in symptoms right away. Notify your doctor if your symptoms don’t improve within one month of taking the medication.

Possible side effects of cromolyn sodium include:

  • headaches
  • nasal irritation
  • cough
  • wheezing
  • dizziness
  • nausea
  • body aches
  • drowsiness

Talk to your doctor if you experience any of these side effects while taking cromolyn sodium. Your doctor may adjust your dosage or switch you to another medication. Don’t stop your medication or make any changes to your dosage without speaking to your doctor first.

For a time, cromolyn sodium represented a breakthrough in the prevention of allergy-induced asthma. The medication significantly helps to reduce asthmatic episodes triggered by an allergic reaction. In recent years, however, newer leukotriene inhibitor drugs have largely replaced medications containing cromolyn sodium. Leukotriene inhibitors are believed to be more convenient and safe than cromolyn sodium. Cromolyn sodium must be inhaled at least three times per day, while leukotriene inhibitors only need to be taken once per day.

The use of cromolyn sodium for the prevention of asthmatic episodes has declined. However, it’s starting to be used in a topical treatment for atopic dermatitis in children. Atopic dermatitis is an allergic inflammatory skin condition that causes an itchy, painful rash. When applied directly to the skin, cromolyn sodium reduces the symptoms of atopic dermatitis safely and effectively. Cromolyn sodium isn’t absorbed into the bloodstream when it’s applied to the skin. This eliminates any concerns about side effects.

Cromolyn sodium is also useful for treating allergic conjunctivitis. This condition may occur when allergens trigger inflammation in the lining of the eyelids. This can cause extreme eye redness and irritation.


Are there any risks associated with using cromolyn sodium?

Anonymous patient


You should not use this drug if you have had allergic reactions to products that contain cromolyn sodium.

Alan Carter, PharmDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
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