Mast cell stabilizers are medications used to combat allergy symptoms and allergic asthma. The drugs reduce or prevent allergy symptoms (e.g., swelling, itching, runny nose) when taken regularly. While they have very few side effects, they are not as effective as antihistamines, and they take longer to work.

The medications are taken regularly to treat a variety of allergy symptoms and prevent asthma attacks due to an allergic cascade. Many types of mast cell stabilizers also treat inflammation, reducing swelling or constricted airways to restore normal breathing. The medications usually work for four to eight hours, and must be taken regularly up to two to four weeks for full effect.

The medication is available in several different forms, including:

• Inhaled treatments (e.g., inhaler, nebulizer)
• Ophthalmic (related to the eye) treatments (e.g. eye drops)
• Nasal treatments (e.g., nasal spray)
• Oral treatments (e.g., pills, liquid)

There are generally few side effects associated with mast cell stabilizers, and those effects are usually mild. This makes the drug useful for individuals with many types of pre-existing conditions, as well as the elderly and children. Children as young as 2 can safely use some forms of mast cell stabilizers.