Cromolyn sodium is a medication used to prevent and manage certain allergic and inflammatory conditions. It belongs to a class of drugs known as mast cell stabilizers and is derived from a substance in the Ammi visnaga plant. Unlike some other allergy medications, cromolyn sodium is not a steroid. Its primary function is to stop allergic reactions before they start, rather than treating symptoms after they have appeared.
How Cromolyn Sodium Works
To understand how cromolyn sodium works, it is necessary to know about mast cells. These are specialized immune cells involved in the body’s allergic response. When exposed to a substance you are allergic to, like pollen, your body produces antibodies that attach to these mast cells. The next time you encounter that allergen, it binds to these antibodies and signals the mast cells to break open, a process called degranulation.
This degranulation releases chemicals, including histamine and leukotrienes, into your tissues. These chemicals are responsible for the symptoms of an allergic reaction, like sneezing, itching, swelling, and bronchoconstriction. Cromolyn sodium works by stabilizing the outer membrane of the mast cells. This prevents them from rupturing and releasing their inflammatory contents when triggered by an allergen.
Because of this mechanism, cromolyn sodium is a preventative medication. It must be taken regularly before exposure to an allergen to be effective and does not provide relief for symptoms that have already begun. Its effects on a mast cell last for approximately six hours after it is administered.
Medical Uses of Cromolyn Sodium
The preventative action of cromolyn sodium makes it suitable for managing several chronic allergic conditions. One of its most common applications is for allergic rhinitis, also known as hay fever. It helps prevent the nasal symptoms of sneezing, itching, and a runny nose triggered by airborne allergens.
For individuals with asthma, cromolyn sodium is used as a maintenance therapy to prevent attacks, particularly those induced by allergies or exercise. It is not a rescue inhaler and is ineffective for treating an acute asthma attack already in progress. Another use is for allergic conjunctivitis, where it helps control the itching, redness, and watering of the eyes.
The medication is also prescribed for mastocytosis, a rare condition involving an excessive number of mast cells. For these patients, oral cromolyn sodium can help manage gastrointestinal symptoms and skin issues like flushing and itching. The oral form is also sometimes used off-label to prevent reactions to certain food allergies.
Forms of Administration
Cromolyn sodium is not well absorbed by the body, so it must be applied directly to the area where the allergic reaction occurs. This has led to several forms of the medication, each tailored to a specific condition.
For allergic rhinitis, a nasal spray delivers the medication to the nasal passages. Preventative treatment for asthma is administered as a solution through a nebulizer, which turns the liquid into a fine mist that can be inhaled into the lungs.
Eye allergies are treated with an ophthalmic solution in the form of eye drops. For systemic conditions like mastocytosis and food allergies, an oral solution is prescribed. This form comes in ampules that are mixed with water and taken before meals.
Potential Side Effects
Side effects of cromolyn sodium are generally mild and localized to the area of application. Because little of the drug is absorbed into the bloodstream, systemic side effects are less common and depend on the form of administration.
Users of the nasal spray may experience temporary sneezing or a burning sensation in the nose. Those using eye drops might feel a brief stinging in their eyes. When cromolyn sodium is inhaled, it can sometimes cause throat irritation or a cough. The oral solution is associated with headache, diarrhea, and abdominal pain.
While uncommon, a more serious allergic reaction to the medication itself is possible. Symptoms such as hives, swelling of the face or tongue, or difficulty breathing require immediate medical attention. Patients should discuss any side effects with their doctor.