Generic Name: montelukast
Brand Name: Singulair
Drug Class: Leukotriene Receptor Antagonists
What is montelukast, and what is it used for?
Montelukast is an oral leukotriene receptor antagonist that is used for the treatment of asthma and seasonal allergic rhinitis (hay fever).
Leukotrienes are a group of naturally occurring chemicals in the body that promote inflammation in asthma and seasonal allergic rhinitis and in other diseases in which inflammation is important (such as allergy). They are formed by cells, released, and then bound to other cells that cause inflammation. It is the binding to other cells that stimulates the cells to cause inflammation. Montelukast works in a manner similar to zafirlukast (Accolate), blocking the binding of some leukotrienes to the cells that cause inflammation.
Unlike zafirlukast, montelukast does not inhibit CYP2C9 or CYP3A4, two enzymes in the liver that are important in breaking down and eliminating many drugs. Therefore, unlike zafirlukast, montelukast is not expected to affect the elimination of other drugs.
The safety and effectiveness of montelukast has been demonstrated in children as young as 6 months of age. It was approved by the FDA in 1998.
What are the side effects of montelukast?
The most common side effects of montelukast are:
- headache,
- dizziness,
- abdominal pain,
- sore throat, and
- rhinitis (inflammation of the inner lining of the nose).
Other important side effects include:
Elevated liver enzymes, suicidal behavior, fluid retention, depression, and hallucinations have also been reported.
What is the dosage for montelukast?
- The recommended dose of montelukast in adults is 10 mg daily for treating asthma and allergic rhinitis and 10 mg two hours before exercising for prevention of exercise induced bronchospasm.
- Montelukast should be taken in the evening with or without food when used for asthma or allergic rhinitis.
- The 4 and 5 mg tablets are used in children.
Which drugs interact with montelukast?
Phenobarbital, rifampin, and carbamazepine (Tegretol, Tegretol XR, Equertro, Carbatrol) may decrease blood concentrations of montelukast. This may reduce the effect of montelukast.

QUESTION
Asthma is a chronic respiratory disease. See AnswerIs montelukast safe to take if I'm pregnant or breastfeeding?
Montelukast crosses the placenta into the fetus following oral administration to animals, but there have been no adequate studies in pregnant women to determine the effects on the fetus. Physicians may prescribe zafirlukast during pregnancy if it is felt that its benefits outweigh the potential but unknown risks to the fetus.
Studies in animals have shown that montelukast is excreted in milk; however, it is not known if montelukast is secreted into breast milk in humans.
Summary
Montelukast is a drug prescribed for the treatment of asthma and hay fever (seasonal allergic rhinitis). The most common side effects of montelukast are headache, dizziness, abdominal pain, sore throat, and rhinitis (inflammation of the inner lining of the nose). Other important side effects include wheezing, cough, rash, restlessness, tremor, and nausea. Consult your doctor if pregnant or breastfeeding.
Multimedia: Slideshows, Images & Quizzes
-
What Is Asthma? Symptoms, Causes, and Treatments
What is asthma? What is the main cause of asthma? Learn information about asthma, a chronic disease of the bronchiole tubes....
-
Common Allergies: Symptoms and Signs
What are allergies? Pollen, food, perfumes, and many more things can provoke allergy symptoms. Allergies are an overreaction of...
-
Asthma Quiz
Asthma is a chronic disease of the airways of the lungs, which can be managed with proper treatment. Triggered by two main...
-
Allergies Quiz: Symptoms & Home Remedies
What are the causes of allergies? This online quiz challenges your knowledge of common food and household allergens,...
-
10 Signs Your Allergies Are Out of Control
Learn 10 signs your allergies are out of control. See these surprising allergy symptoms and find out how to get relief for...
-
Allergies: 10 Ways to Reduce Mold Allergies
WebMD shows you 10 ways to fight the fungus and reduce mold allergy symptoms from dust masks to bottles of bleach.
-
Nasal Irrigation: Natural Relief for Cold & Allergy Symptoms
Clogged sinuses and congestion bothering you? Nasal irrigation can relieve sinus symptoms associated with colds and allergies....
-
Asthma: Asthma and the Weather
Does the weather affect your asthma? Find out how heat, cold and thunderstorms can make it hard to breathe -- and what you can do...
-
What is Asthma? Asthma Myths Debunked
What are asthma myths and facts? There is currently no cure for asthma, and no specific, single cause for asthma has been...
-
10 Worst Cities for Spring Allergies
See pictures of the top 10 "spring allergy capitals", according to the Asthma and Allergy Foundation of America (AAFA). From...
-
Allergies: Common Plants and Trees That Trigger Allergies
Find out more about which plants and trees might be producing pollen that is causing your itchy eyes and a runny nose.
-
Asthma and Your Diet: Foods That Help and Hurt
Even though there's no specific asthma diet that can help your condition, certain foods may help or harm your breathing. Learn...
-
Allergies: Myths and Facts About Seasonal Allergies
Seasonal allergy symptoms are hard. Do deserts prevent allergies? What can allergies do to your body? What is an allergen? Adult...
-
Asthma Attacks: Triggers, Symptoms, and Treatment
Asthma symptoms include coughing, wheezing, headache, fatigue, dark circles under the eyes, trouble sleeping, and loss of...
-
Asthma: Common Inhaler Mistakes
An inhaler helps you breathe better, but you might not be getting the full effect. Find out how to get the most out of your...
-
Asthma: Natural Ways to Ease Asthma Symptoms
You can do more than take medication to manage your asthma. Several other things can help you breathe more easily.
-
12 Natural Ways to Defeat Allergies
Allergies making you miserable? WebMD shows you a dozen natural allergy treatments, from fresh fruit and vitamin D to acupuncture...
Related Disease Conditions
-
How Long Does an Allergic Reaction Last?
Allergic reactions may last for varying lengths of time. They may take a few hours to a few days to disappear. If the exposure to the allergen continues, such as during a spring pollen season, allergic reactions may last for longer periods such as a few weeks to months.
-
Drug Abuse and Addiction
Drug abuse and addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and those around him. Though the initial decision to use drugs is voluntary, changes in the brain caused by repeated drug abuse can affect a person's self-control and ability to make the right decisions and increase the urge to take drugs. Drug abuse and addiction are preventable.
-
Chronic Rhinitis and Post-Nasal Drip
Chronic rhinitis (non allergic rhinitis) causes runny nose, sneezing, nasal itching and congestion. Post-nasal drip is drainage of mucus from the sinuses into the throat. Treatment includes over-the-counter (OTC) medications.
-
Hives (Urticaria)
Hives, also called urticaria, is a raised, itchy area of skin. Most often the cause of hives is unknown. Sometimes it is a sign of an allergic reaction to food or medications, but the cause of the allergy (the allergen) is unknown. Dermatographism and swelling (angioedema) may accompany hives. Treatment to get rid of hives and alleviate symptoms typically includes antihistamines.
-
Allergy (Allergies)
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
-
What Are the 4 Types of Allergic Reactions?
Allergists recognize four types of allergic reactions: Type I or anaphylactic reactions, type II or cytotoxic reactions, type III or immunocomplex reactions and type IV or cell-mediated reactions.
-
Anxiety
Anxiety is a feeling of apprehension and fear characterized by symptoms such as trouble concentrating, headaches, sleep problems, and irritability. Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. Treatment for anxiety may incorporate medications and psychotherapy.
-
COPD vs. Asthma (Differences and Similarities)
COPD (chronic obstructive pulmonary disease) and asthma both have common symptoms like coughing, wheezing, shortness of breath, and a tight feeling in the chest. COPD is caused by tobacco smoking, while asthma is caused by your inherited genetic makeup and their interactions with the environment. Risk factors for asthma are obesity, exposure to cigarette smoke (even secondhand smoke), and personal history of hay fever. There is no cure for either disease, but symptoms can be managed with medication. A person with asthma has a better prognosis and life expectancy than someone with COPD.
-
Depression
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
-
Neutropenia
Neutropenia is a marked decrease in the number of neutrophils, neutrophils being a type of white blood cell (specifically a form of granulocyte) filled with neutrally-staining granules, tiny sacs of enzymes that help the cell to kill and digest microorganisms it has engulfed by phagocytosis. Signs and symptoms of neutropenia include gum pain and swelling, skin abscesses, recurrent ear and sinus infections, sore mouth, low-grad fever, pneumonia-like symptoms, and pain and irritation around the rectal area. Neutropenia has numerous causes, for example, infections (HIV, TB, mono); medications (chemotherapy); vitamin deficiencies (anemia); bone marrow diseases (leukemias), radiation therapy, autoimmune destruction of neutrophils, and hypersplenism. Treatment of neutropenia depends upon the cause and the health of the patient.
-
Asthma
Asthma is a condition in which hyperreactive airways constrict and result in symptoms like wheezing, coughing, and shortness of breath. Causes of asthma include genetics, environmental factors, personal history of allergies, and other factors. Asthma is diagnosed by a physician based on a patient's family history and results from lung function tests and other exams. Inhaled corticosteroids (ICS) and long-acting bronchodilators (LABAs) are used in the treatment of asthma. Generally, the prognosis for a patient with asthma is good. Exposure to allergens found on farms may protect against asthma symptoms.
-
Hay Fever (Allergic Rhinitis)
Hay fever (allergic rhinitis) is an irritation of the nose caused by pollen and is associated with the following allergic symptoms: nasal congestion, runny nose, sneezing, eye and nose itching, and tearing eyes. Avoidance of known allergens is the recommended treatment, but if this is not possible, antihistamines, decongestants, and nasal sprays may help alleviate symptoms.
-
Asthma Over-the-Counter Treatment
Patients who have infrequent, mild bouts of asthma attacks may use over-the-counter (OTC) medications to treat their asthma symptoms. OTC asthma medicines are limited to epinephrine and ephedrine. These OTC drugs are best used with the guidance of a physician, as there may be side effects and the drugs may not be very effective.
-
How Can I Treat My Child's Asthma at Home?
Treatment of a child's asthma involves following an action plan developed in consultation with your child's pediatrician. Severe asthmatic attacks require immediate medical attention and treatment at the hospital.
-
What Is the Treatment for Asthmatic Bronchitis?
Asthmatic bronchitis refers to inflammation of the bronchial tubes carrying air inside the lungs that occurs because of asthma. Treatment for asthmatic bronchitis involves bronchodilators, steroids, treating secretions, leukotriene inhibitors, antibiotics, oxygen administration and avoiding triggers.
-
Cold, Flu, Allergy Treatments
Before treating a cold, the flu, or allergies with over-the-counter (OTC) medications, it's important to know what's causing the symptoms, which symptoms one wishes to relieve, and the active ingredients in the OTC product. Taking products that only contain the medications needed for relieving your symptoms prevents ingestion of unnecessary medications and reduces the chances of side effects.
-
Can Asthma Damage Your Lungs?
Asthma inflames the inner lining of the respiratory tubes and tightens the smooth muscles surrounding the airways, and can cause irreversible damage to your lungs if the condition is not controlled well.
-
Asthma Medications
There are two types of asthma medications: long-term control with anti-inflammatory drugs and quick relief from bronchodilators. Asthma medicines may be inhaled using a metered-dose inhaler or nebulizer or they may be taken orally. People with high blood pressure, diabetes, thyroid disease, or heart disease shouldn't take OTC asthma drugs like Primatene Mist and Bronkaid.
-
Allergy Treatment Begins at Home
Avoiding allergy triggers at home is one of the best ways to prevent allergy symptoms. Controlling temperature, humidity, and ventilation are a few ways to allergy-proof the home. Cleaning, vacuuming, and using HEPA air filters also helps control allergies.
-
Adult-Onset Asthma
Adult-onset asthma is asthma that is diagnosed in people over 20 years of age. Symptoms include wheezing, coughing, shortness of breath and difficulty breathing. Treatment may involve anti-inflammatory medications or bronchodilators.
-
Asthma in Children
Asthma in children manifests with symptoms such as coughing and wheezing. Rates of asthma in children are increasing. Asthma in children is usually diagnosed based on the description of symptoms. Lung function tests may also be used. A variety of medications are used for the treatment of childhood asthma.
-
Teen Drug Abuse
Drugs commonly abused by teens include tobacco products, marijuana, cold medications, inhalants, depressants, stimulants, narcotics, hallucinogens, PCP, ketamine, Ecstasy, and anabolic steroids. Some of the symptoms and warning signs of teen drug abuse include reddened whites of eyes, paranoia, sleepiness, excessive happiness, seizures, memory loss, increased appetite, discolored fingertips, lips or teeth, and irritability. Treatment of drug addiction may involve a combination of medication, individual, and familial interventions.
-
What Is Allergic Cascade?
The allergic cascade refers to allergic reactions that happen in the body in response to allergens. A variety of immune cells and chemical messengers participate in the allergic cascade. Symptoms of the allergic cascade range from mild swelling and itching to full-blown anaphylactic shock. Allergen avoidance and medications are used to prevent or treat allergies.
-
What Is Asthma? 19 Complex Facts
There are many unusual symptoms of asthma, including sighing, difficulty sleeping, anxiety, chronic cough, recurrent walking pneumonia, and rapid breathing. These symptoms may vary from individual to individual. These asthma complexities make it difficult to accurately diagnose and treat asthma.
-
Sinus Infection vs. Allergies
Both sinus infections and allergies (allergic rhinitis) cause symptoms such as runny or stuffy nose and fatigue. Sinus infection (known as sinusitis) is inflammation of the sinuses, caused by infection from bacteria, viruses, and/or fungi (molds). Allergic rhinitis occurs when certain allergies cause nasal symptoms. When a person with allergies breathes in an allergen, such as pollen, dust, or animal dander, symptoms such as runny or stuffy nose, itching, sneezing, and fatigue occur.
-
What Is the Difference Between Allergy and Hay Fever?
Hay fever is a type of allergy that occurs in response to specific allergens and typically lasts for months. Learn more about allergies vs. hay fever.
-
Drug Allergy (Medication Allergy)
Drug or medication allergies are caused when the immune system mistakenly creates an immune response to a medication. Symptoms of a drug allergic reaction include hives, rash, itchy skin or eyes, dizziness, nausea, diarrhea, fainting, and anxiety. The most common drugs that people are allergic to include penicillins and penicillin type drugs, sulfa drugs, insulin, and iodine. Treatment may involve antihistamines or corticosteroids. An EpiPen may be used for life-threatening anaphylactic symptoms.
-
Can Asthma Go Away on Its Own?
Asthma is a long-term condition for many people, particularly if it first develops when you're an adult. In children, it sometimes goes away or improves during the teenage years, but can come back later in life.
-
COVID-19 vs. Allergies
Though there is some overlap in allergy and COVID-19 signs and symptoms there are also significant differences. Symptoms that they have in common include headache, fatigue, tiredness, shortness of breath, wheezing, and sore throat. Fever does not occur with allergies but is one of the defining symptoms of COVID-19 infections.
-
How Do You Know if You Have Asthma or Not?
Your doctor may diagnose you with asthma based upon your signs and symptoms and after performing a physical exam and certain tests.
-
What Are the 4 Most Common Allergens?
The four most common types of allergens include food and medications, pollen, pet dander, and latex.
-
Occupational Asthma
Occupational asthma is a type of asthma caused by exposure to a substance in the workplace. Symptoms and signs include wheezing, chest tightness, and shortness of breath. The usual treatment for occupational asthma involves removal from exposure and the use of bronchodilators and inhaled anti-inflammatory medicines.
-
Can You Exercise With Exercise-Induced Asthma?
You can continue exercise and normal physical activity even after being diagnosed with exercise-induced asthma (EIA).
-
What Are the Four Types of Asthma?
Asthma is a chronic inflammatory disease of the airways (bronchi). Bronchi generally allow for the passage of air in and out of the lungs. In asthma, these airways develop hypersensitivity, inflammation, and narrowing. This causes difficulty in breathing. The four types are mild intermittent, mild persistent, moderate persistent, and severe persistent.
-
What Causes Nose Allergies?
Nose allergies can be caused by irritants such as pollen, animal dander, and household dust. Learn about symptoms, treatment, and prevention.
-
What 5 Things Signal an Asthma Attack?
Understand the five symptoms of an asthma attack to better get the treatment you need during an episode.
-
How Do You Know if Your Baby Has Asthma?
Properly diagnosing and managing asthma in babies and young children can be challenging. However, be on the lookout for these signs and symptoms.
-
What Is Winter Asthma?
Why is your asthma worse in the colder months? Learn about causes of winter asthma and what you can do now to create an action plan.
-
What Is the Best Treatment for Asthma?
Depending on the severity of your asthma, treatment may include quick-relief or controller medicines, a combination of both or the use of biologics.
-
How Does Asthma Start?
Though asthma symptoms may come on suddenly without any prior noticeable change, sometimes, an asthma attack typically starts with a few early warning signs.
-
How Is COVID-19 Different From Allergies?
COVID-19 symptoms are often similar to symptoms of seasonal allergies, so it is important to know how to tell the difference. Learn how to distinguish between the two.
-
How Do You Tell If Your Child Has Allergies or a Cold?
Colds and allergies have different causes, but both involve the body's immune system. Since the symptoms of allergies and the symptoms of a cold overlap, it can be hard to tell which one your child has.
-
What Class Is Severe Asthma?
Asthma is termed as a chronic inflammatory lung disease caused by the airway’s hypersensitive response to allergic stimuli (dust, pollen, pollution, smoke or unhygienic conditions). This results in the narrowing of airway passages, making it hard to breathe. It is often genetic and passed down from families and precipitated during childhood.
-
What Is Severe Asthma?
Asthma is a chronic inflammatory lung disease caused due to the airway’s hypersensitive response to allergic stimuli. Severe asthma or status asthmaticus is defined as asthma that is uncontrolled, despite adherence with maximal optimized therapy and treatment of contributory factors or asthma that worsens when high dose treatment is decreased.
Treatment & Diagnosis
- Allergies FAQs
- Asthma FAQs
- Hay Fever: Managing Hay Fever Symptoms
- What if I Get COVID-19 with Asthma?
- Medication Disposal
- Dangers of Mixing Medications
- Drugs: The Most Common Medication Errors
- Asthma in Women, Asthma in Pregnancy
- Asthma Rates Increasing
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Drugs: Buying Prescription Drugs Online Safely
- Can Asthma Medication Hide Churg-Strauss Syndrome?
- What Is the Treatment for Hay Fever?
- What Is Exercise-Induced Asthma?
- Can Asthma Go Away and Come Back?
- What Are the Side Effects of Asthma Inhalers?
- Does Altitude Affect Asthma?
- Best Exercises for Asthma: Yoga, Swimming, Biking, and Walking
- Does Stress Cause Asthma?
- Can Asthma Cause a Heart Attack?
- What Causes Asthma?
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
Prevention & Wellness

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
REFERENCE:
FDA Prescribing Information