Three drugs that have been approved by the Food and Drug Administration (FDA), montelukast (Singulair), zafirlukast (Accolate), and zileuton (Zyflo), block the action of leukotrienes to help prevent and treat the symptoms of asthma. Montelukast has also been approved to relieve symptoms of allergic rhinitis.
Asthma and Allergic Rhinitis
is a chronic lung disease. When asthma strikes, airways in the lungs become inflamed and constricted, causing coughing, wheezing, and difficulty breathing. According to the American Academy of Allergy, Asthma, and Immunology, asthma affects 20 million Americans.
is an allergic response by your immune system to pollens, mold, and dust. It affects about 10% of the population. Symptoms include stuffy, runny, or itchy nose, and sneezing. Children are much more likely to develop allergies if their parents have allergies.
Asthma and allergic rhinitis are both allergic conditions. They can be triggered by many of the same allergens. And, in both conditions, leukotrienes contribute to the development of symptoms. Leukotrienes are hormones that are derived from arachidonate (arachidonic acid) and are produced by white blood cells. They cause inflammation, fluid retention, mucous secretion, and constriction in your lungs.
How Leukotriene Inhibitors Work
Montelukast, zafirlukast, and zileuton are all nonsteroidal anti-inflammatory medications and work to prevent symptoms by preventing the action of leukotrienes. Montelukast and zafirlukast work by competitively inhibiting leukotrienes, meaning they compete with leukotrienes in the blood to attach to leukotriene receptors on certain cell surfaces. Zileuton works by stopping the action of an enzyme (5-lipoxygenase), which in turn inhibits leukotriene formation.
Leukotriene receptors are not used to relieve acute symptoms, but can be used for prophylactic or chronic therapy. They also do not block histamines (as do popular antihistamine medications, like Benadryl and Claritin).
The side effects of montelukast, zafirlukast, and zileuton are usually mild and are similar to those reported by patients who were given a placebo. Some of the most common side effects with these drugs are:
Stomach pain or upset
Less common side effects include itching, fever, joint pain, muscle aches, and autoimmune reactions.
Who Should or Should Not Take Leukotriene Inhibitors
In deciding whether or not to take a particular medication, the benefits must be weighed against the risks. You and your doctor will decide what’s best for you. For leukotriene receptor agonists, the following ought to be considered:
Allergies—You should not take these drugs if you are allergic to any of their ingredients.
Other medical problems—The presence of other medical problems may affect the use of these drugs. Tell your doctor about any medical problems you have now or had in the past, especially liver disease, which could increase your chance of serious side effects.
Pregnancy—These drugs, while considered safe, have not been studied in pregnant women.
Breastfeeding—Consult your doctor if you are breastfeeding or intend to breastfeed.
Children—The chewable tablet form of montelukast contains phenylalanine. This medicine affects those with
Other medications—Certain medications should not be used together. Tell your doctor if you are taking or using any other prescription (theophylline, warfarin, propanolol, phenobarbital, and inhaled corticosteroids in particular) or over-the-counter medications, including herbs and supplements.
For more information on medications for asthma or allergies, talk to your doctor.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a