Specifically, the Food and Drug Administration (FDA) has approved Singulair for:
This article describes possible side effects of Singulair. You can explore this overview article to learn more about Singulair, including the drug’s uses, ways to save on cost, and more.
Singulair is a brand-name medication available as oral tablets, chewable tablets, and oral granules.* It’s available in a generic version called montelukast. This article describes the possible side effects of Singulair.
* Oral granules are a powder that you can swallow or mix into liquids or certain soft foods before swallowing.
Boxed warning: Risk of serious behavior or mood changes
Singulair has a boxed warning for the risk of serious behavior or mood changes. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).
For details, see the “Side effects of Singulair in detail” section below.
More common side effects of Singulair
Singulair may cause mild or serious side effects. Below are some of the more common side effects of this medication.
Commonly reported side effects of Singulair include:
- headache
- abdominal pain
- cough
- indigestion (upset stomach)
- infection*
* To learn more about this side effect, see the “Side effects of Singulair in detail” section below.
Mild side effects of Singulair
Singulair may cause certain mild side effects. Most often, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.
Mild side effects of Singulair that occurred in studies include:
Singulair may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.
* To learn more about this side effect, see the “Side effects of Singulair in detail” section below.
† An allergic reaction is possible with Singulair. But it wasn’t reported in the drug’s studies.
Serious side effects of Singulair
Singulair may cause certain serious side effects. If you have any serious side effects from Singulair, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.
After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with Singulair.
Serious side effects of Singulair that occurred in studies include:
* Singulair has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects of Singulair in detail” section below.
† To learn more about this side effect, see the “Side effects of Singulair in detail” section below.
‡ An allergic reaction is possible with Singulair. But it wasn’t reported in the drug’s studies.
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Side effects of Singulair in children
For children, doctors prescribe Singulair to:
In studies, certain side effects were reported in children that weren’t reported in adults. Examples include:
If you’d like to know more about side effects in children taking Singulair, talk with your doctor or pharmacist.
Common questions about side effects of Singulair
Here are answers to some common questions about side effects of Singulair. If you have other questions, talk with your doctor or pharmacist.
Does Singulair cause long-term side effects?
Yes, in some cases. Singulair carries a risk of serious behavior or mood changes that can last for a while after you’ve stopped taking the drug.
In fact, Singulair has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects of Singulair in detail” section below.
You can also talk with your doctor to learn more about this side effect and how long it may last.
Is Singulair safe for older adults?
Yes, Singulair is considered safe for most older adults (people age 65 years and older). Specific side effects haven’t been reported in older adults who’ve taken Singulair.
That said, older adults may be more sensitive to the side effects of Singulair. For this reason, doctors may watch closely for side effects after prescribing Singulair for older adults.
Talk with your doctor or pharmacist if you have questions about how your age may affect the safety of Singulair.
Side effects of Singulair in detail
Below you’ll find details on some of the side effects of Singulair.
Risk of serious behavior or mood changes
Singulair has a boxed warning for the risk of serious behavior or mood changes. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).
Serious behavior or mood changes weren’t reported in studies of Singulair. But they have been reported since the drug became available for use. This side effect may be serious. It could occur while taking the drug or after treatment is stopped.
Examples of serious behavior or mood changes include:
Due to the risk of serious behavior or mood changes, doctors only prescribe Singulair if the benefits of treatment are greater than this risk.
Ways to manage
If you experience serious behavior or mood changes, tell your doctor right away. They’ll likely recommend stopping Singulair and switching to a different treatment.
If you have suicidal thoughts or behaviors, call the 988 Suicide and Crisis Lifeline or seek emergency medical care.
Infection
In studies, infections such as influenza (the flu), ear infection, and upper respiratory infection were common in people taking Singulair. The side effect is usually mild.
Symptoms vary depending on the specific infection and may include:
- chills or fever
- body aches
- cough
- pressure or pain inside your ear
Ways to manage
If you experience symptoms of infection, tell your doctor. They’ll likely give you tests to check for infection and can tell you whether you require treatment.
Your doctor may also recommend over-the-counter (OTC) options for easing infection symptoms. Examples include acetaminophen (Tylenol) to reduce fever and dextromethorphan (Delsym) to ease cough.
Diarrhea
In studies, diarrhea was common in people taking Singulair. This side effect is usually mild.
With diarrhea, symptoms may include loose, watery, or frequent stools.
Ways to manage
If you have severe or bothersome diarrhea with Singulair, tell your doctor. They may recommend taking your Singulair doses with food to help ease this side effect.
Your doctor may also recommend OTC options, such as bismuth subsalicylate (Pepto Bismol), to ease diarrhea.
For some people, Singulair can cause an allergic reaction. But this side effect wasn’t reported in the drug’s studies.
Symptoms can be mild or serious and may include:
- itchiness
- skin rash
- swelling under the skin, usually affecting eyelids, lips, hands, or feet
- swelling of the mouth, tongue, or throat, which can make it hard to breathe
- flushing (temporary warmth, redness, or deepening of skin color)
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Singulair, your doctor may recommend taking a different medication instead.
Suicide prevention
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you are not in the same household, stay on the phone with them until help arrives.
Warnings for Singulair
Below are some factors you may want to discuss with your doctor before taking Singulair.
Boxed warning: Risk of serious behavior or mood changes
Singulair has a boxed warning for the risk of serious behavior or mood changes. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).
For details, see the “Side effects of Singulair in detail” section above.
Other warnings
It may not be safe for you to take Singulair if you have specific health conditions. These are sometimes called drug-condition interactions. Other factors may also affect whether Singulair is a safe treatment option for you.
Before taking Singulair, tell your doctor about your health and medications you take. Things to consider include:
Singulair and pregnancy
In general, Singulair is considered safe to take during pregnancy. That said, check with your doctor about whether they feel it’s safe for you specifically.
Singulair and breastfeeding
In general, Singulair is considered safe to take while breastfeeding. That said, check with your doctor about whether they feel it’s safe for you specifically.
Singulair is not known to interact with alcohol.
But keep in mind that Singulair may cause high levels of liver enzymes (special proteins made in the liver). This side effect could be a sign of liver damage. Consuming large amounts of alcohol while taking the drug may further increase the risk of liver damage.
If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with Singulair.
What to ask your doctor
This article describes common and serious side effects of Singulair. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.
Here’s a list of questions you may want to ask your doctor:
- Does my health history raise my risk of side effects from Singulair?
- How do the side effects of Singulair compare with those of other drugs that treat my condition?
- Is my risk of side effects higher when I first start Singulair treatment?
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
