Exactly how mast cell stabilizers work to control asthma is unclear, but they are thought to strengthen the membranes of a type of white blood cells called mast cells. Unlike other white blood cells that circulate around the body, mast cells collect in certain tissues including the lungs. Mast cells are filled with tiny granules of substances such as histamine. When mast cells are activated by irritants, they degranulate (break down) and the substances they contain are released into the body. In the lungs, these substances make bronchial tubes (airways) contract, cause inflammation, increase mucus production, and promote swelling. Additionally, activated mast cells produce or attract other chemicals that can worsen and prolong inflammation. By keeping the mast cells from breaking down, mast cell stabilizers prevent or decrease inflammatory components of asthma.

Drugs in this Class
Cromolyn Inhaler (Intal Inhaler)
Nedocromil Inhaler (Nedocromil Hydrochloride Inhaler, Tilade Inhaler)

Summarizing the Evidence

• Study results show that cromolyn and nedocromil are about equally effective at controlling asthma symptoms.
• Neither mast cell stabilizer is as effective as inhaled corticosteroids in the long-term control of asthma.
• Because they have very few side effects, mast cell stabilizers commonly are used for children or seniors with asthma. According to the U.S. National Institutes of Health's Guidelines for the Diagnosis and Management of Asthma, either cromolyn or nedocromil may be used by both children and adults as an alternative to inhaled corticosteroids for long-term asthma control therapy.
• Neither mast cell stabilizer can be used for the immediate relief of an acute asthma attack, however.
• Although nedocromil is not FDA-approved for preventing asthma symptoms, both mast-cell stabilizing drugs may be used as preventive treatment prior to exercise or unavoidable exposure to known asthma triggers.
• Cromolyn is FDA-approved for use by adults and children who are at least 5 years of age. Nedocromil is for adults and children 6 years of age and older.

Dosing and Administration

• Cromolyn is usually inhaled by mouth three times or four times a day to prevent asthma attacks. The recommended dose for adults is two puffs to four puffs at a time (up to 16 puffs a day). Children age 12 and under should use one puff or two puffs at a time (up to eight puffs per day) of the inhaler or one ampule of the nebulizer solution three times or four times a day. Cromolyn may also be taken up to an hour before vigorous activities to prevent breathing difficulties caused by exercise.
• Currently available only as a brand-name inhaler, nedocromil may be inhaled by mouth up to four times a day to prevent asthma attacks. Recommended doses for adults are two puffs to four puffs at a time (up to 16 puffs a day) and for children age 12 and under one puff or two puffs at a time (up to eight puffs per day).
• Some individuals report a bitter taste in the mouth after using nedocromil.

Generic Availability

• Cromolyn comes as both brand (Intal) and generic solutions for nebulizers or as a brand-name aerosol (Intal) to inhale by mouth.
• Nedocromil comes only as a brand-name aerosol (Tilade) to inhale by mouth.

Drug Interactions

Some interactions between medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how the drugs interact and the severity of the interaction, please use our Drug Interactions Checker.

Side Effects

To view specific side effect information, please use our Side Effect Checker.

Additional Information

References

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Boldy DA, Ayres JG. Nedocromil sodium and sodium cromoglycate in patients aged over 50 years with asthma. Respir Med. 1993;87:517-523.

Bradding P, Walls AF, Holgate ST. The role of the mast cell in the pathophysiology of asthma. J Allergy Clin Immunol. 2006;117(6):1277-1284.

Comis A, Valletta EA, Sette L, et al. Comparison of nedocromil sodium and sodium cromoglycate administered by pressurized aerosol, with and without a spacer device in exercise-induced asthma in children. Eur Respir J. 1993; 6(4): 523-526.

de Benedictis FM, Tuteri G, Bertotto A, et al. Comparison of the protective effects of cromolyn sodium and nedocromil sodium in the treatment of exercise-induced asthma in children. J Allergy Clin Immunol. 1994; 94(4): 684-688.

de Benedictis FM, Tuteri G, Pazzelli P, et al. Cromolyn versus nedocromil: duration of action in exercise-induced asthma in children. J Allergy Clin Immunol. 1995; 96(4): 510-4.

Drugdex Database. In: Gelman CJ, Rumack BH, editors. Denver: Micromedex Inc. 2000.

Guevara JP, Ducharme FM, Keren R, Nihtianova S, Zorc J. Inhaled corticosteroids versus sodium cromoglycate in children and adults with asthma. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD003558.

Holgate ST. Reflections on the mechanism(s) of action of sodium cromoglycate (Intal) and the role of mast cells in asthma. Respir Med. 1989;83(Suppl A):25-31.

Holian A, Hamilton R, Scheule RK. Mechanistic aspects of cromolyn sodium action on the alveolar macrophage: inhibition of stimulation by soluble agonists. Agents Actions. 1991;33(3-4):318-325.

Intal [package insert]. Loughborough, England: Healthcare Specialties Division, 3M Health Care Limited; September 2005.