Dulera (mometasone and formoterol) is a prescription inhaler that’s used to treat asthma. Dulera can cause side effects that range from mild to serious. Examples include headache and inflammation of the nose, throat, and sinuses.

Specifically, Dulera is approved to treat asthma in adults and children ages 5 years and older. Dulera will not stop sudden asthma symptoms such as severe wheezing or difficulty breathing. You will need a rescue inhaler to treat sudden asthma symptoms.

The active ingredients in Dulera are mometasone and formoterol. (An active ingredient is what makes a drug work.) The drug comes as a mist that you inhale using a pressurized metered dose inhaler.

Keep reading to learn about the common, mild, and serious side effects that Dulera can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during their Dulera treatment. Here are only a few examples of the drug’s commonly reported side effects:

  • inflammation of the sinuses, throat, and nose
  • headache

Mild side effects have been reported with Dulera. These include:

In most cases, these side effects should be temporary. And some may be easily managed with over-the-counter (OTC) medications and home remedies. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop using Dulera unless your doctor recommends it.

Dulera may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using Dulera. Studies did not report any allergic reactions, but the FDA received reports after approving the drug for public use.

Serious side effects have been reported with Dulera. These include:

  • heart problems, such as arrhythmia, rapid heart rate, and high blood pressure
  • nervous system problems, such as anxiety and shakiness
  • osteoporosis (weakened bones)
  • hypercorticism (high levels of cortisol in the body)
  • adrenal insufficiency (low adrenal gland function)
  • low blood potassium levels
  • high blood sugar
  • glaucoma and cataracts
  • withdrawal symptoms, such as muscle pain, weakness, and depression
  • paradoxical bronchospasm (tightening of the airway that makes it harder to breathe)
  • increased risk of infections*
  • fungal infection in mouth and throat*
  • severe allergic reaction*†

If you develop serious side effects while using Dulera, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using Dulera. Studies did not report any allergic reactions, but the FDA received reports after approving the drug for public use.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Dulera, visit MedWatch.

Dulera metered dose inhaler is used to help treat asthma in children ages 5 and older. Researchers do not know whether Dulera is safe and effective in children younger than 5 years old.

In the drug’s studies, Dulera showed similar side effects in children and adults. However, medications containing corticosteroids such as Dulera are more commonly reported to cause slowed growth in children than in adults.

For more information about potential side effects of Dulera in children, talk with your doctor or pharmacist.

Get answers to some frequently asked questions about Dulera’s side effects.

How long do side effects of Dulera usually last?

For most people, side effects such as inflammation of the sinuses, throat, and nose and headache may last 1–2 weeks. These symptoms may occasionally reoccur during Dulera treatment and can be managed with OTC medications. Examples of these medications include throat lozenges, cough suppressants, and pain relievers such as acetaminophen.

Other symptoms, such as fungal infections in the mouth or throat, can last longer and may require treatment prescribed by your doctor, such as an antifungal mouth rinse.

Be sure to talk with your doctor before starting any OTC medications. Also, talk with your doctor or pharmacist if you develop long lasting or bothersome symptoms while using Dulera.

Can Dulera cause weight gain or anxiety?

Weight gain and anxiety were not seen as side effects in studies of Dulera.

Oral corticosteroids can lead to weight gain and anxiety, but inhaled corticosteroids, such as Dulera, contain such small amounts of corticosteroids that the likelihood of these side effects is low.

Also, using more than the prescribed amount of Dulera may cause anxiety. This is because formoterol, the bronchodilator ingredient in Dulera, has a stimulating effect.

If you have questions about weight gain or anxiety while using Dulera, talk with your doctor.

Does Dulera cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. They also include side effects that may not go away, even after you stop taking the drug.

Examples of long-term side effects reported in studies of medications in the same drug classification as Dulera include:

  • heart problems, such as arrhythmia, rapid heart rate, and high blood pressure
  • osteoporosis (weakened bones)
  • glaucoma and cataracts
  • increased risk of infections*
  • adrenal insufficiency (decreased adrenal gland function)
  • fungal infection in the mouth and throat*

If you’re concerned about possible long-term side effects from Dulera, talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Side effects explained” section below.

Learn more about some of the side effects Dulera may cause.

Increased risk of infections

Dulera can lead to a weakened immune system, which can cause an increased risk of infection. These effects were reported in studies of Dulera. Although inhaled corticosteroids deliver a much lower dose than the oral form, Dulera may still increase your risk of certain infections, such as:

Symptoms to watch for include:

  • cough, often producing dark green, yellow, or brown mucus
  • sinus drainage
  • eye redness and drainage
  • headache
  • sore throat
  • fever, chills, or night sweats
  • nausea and vomiting
  • fatigue (low energy)
  • shortness of breath
  • weakness
  • body aches

Factors that can increase the risk of infections when using this drug include missing vaccinations and being 65 years old or older. Another factor that can increase this risk is using other medications that can suppress your immune system, such as medications that treat certain types of cancer.

What might help

Talk with your pharmacist or doctor if you are at increased infection risk during Dulera treatment. They’ll likely recommend that you get updated vaccinations before you start using Dulera.

Your doctor may also recommend avoiding contact with people who have ongoing chickenpox or measles infections.

Fungal infection in the mouth and throat

Fungal infection in the mouth and throat was a common side effect reported in studies of Dulera. This infection may cause symptoms such as:

  • a loss of taste or a bad taste in the mouth
  • difficulty in eating or drinking
  • a white coating on the tongue or throat
  • soreness and redness inside the mouth
  • a burning or painful sensation in the mouth or throat
  • an inability to wear dentures or a retainer
  • dry mouth
  • cracks in the corners of the mouth or the lips

Factors that can increase the risk of a fungal infection in the mouth and throat when using this drug include:

  • having diabetes, cancer, or another condition that weakens the immune system
  • using an alcohol-containing mouthwash
  • wearing dentures
  • taking antibiotics
  • smoking
  • drinking alcohol

What might help

At-home remedies such as a saltwater rinse may help manage symptoms of a mild yeast infection in your mouth or throat. But if the infection worsens, causing pain and bleeding, you should talk with your doctor. In these cases, your doctor may need to prescribe an antifungal medication to treat the infection.

To help prevent a fungal infection while using Dulera, you can brush your teeth or rinse your mouth with water after each use of the drug. If you wear dentures, cleaning them regularly and not wearing them to bed can also help prevent fungal infections.

Allergic reaction

Like most drugs, Dulera can cause an allergic reaction in some people. Studies did not report any allergic reactions, but the FDA received reports after approving Dulera for public use.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an antihistamine you swallow, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Dulera, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Dulera, they may have you switch to a different treatment.

Keeping track of side effects

During your Dulera treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Dulera affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before using Dulera.

Warnings

Dulera can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Dulera is a good treatment option for you.

Talk with your doctor about your health history before you use Dulera. Be sure to tell them if any of the following factors apply to you:

  • immune system problems, such as a known allergic reaction to Dulera or one of its components
  • osteoporosis (weak bones)
  • heart problems, such as arrhythmia or high blood pressure
  • high blood pressure
  • history of weak and swollen blood vessels
  • eye problems, such as glaucoma or cataracts
  • worsening asthma symptoms
  • seizures
  • thyroid problems, such as an acute illness caused by high thyroid hormone levels
  • diabetes
  • liver problems, such as high liver enzymes
  • planned surgery
  • previous allergic reaction to Dulera
  • pregnancy
  • breastfeeding

Switching to Dulera from oral corticosteroids

Corticosteroids taken by mouth can stop the production of your body’s life-sustaining steroids, such as cortisol.

Suddenly stopping oral corticosteroids to start inhaled Dulera can cause physical withdrawal symptoms such as:

  • nausea and vomiting
  • fatigue (low energy)
  • weakness
  • sluggishness
  • depression
  • muscle or joint pain
  • low blood pressure

Severe physical withdrawal can lead to coma and death. People who stop oral corticosteroids should follow their doctor’s advice on gradually decreasing the dose.

Alcohol and Dulera

There are no known interactions between alcohol and Dulera.

However, drinking alcohol can worsen fungal infections in your mouth or throat caused by Dulera. If you have a fungal infection, it’s best to avoid drinking alcohol until the infection has cleared up.

If you have questions about consuming alcohol during Dulera treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Dulera

Before starting Dulera treatment, it’s essential to talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed.

Pregnancy

It’s not known whether it’s safe to use Dulera during pregnancy. There haven’t been any studies on using Dulera in people who are pregnant.

Asthma that’s not well-controlled during pregnancy may lead to a higher risk of preeclampsia. It can also increase the chances that the child will be born early or weigh less at birth.

Also, there aren’t any studies on the effects of Dulera during labor and childbirth. Since Dulera might affect muscle contractions in the womb, its use during labor should be limited to cases where the benefits are greater than the risks.

Breastfeeding

It isn’t known whether Dulera is safe to use while breastfeeding. There are no studies on whether Dulera is present in human breast milk, how it affects a child who is breastfed, or how it affects milk production.

If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Like most drugs, Dulera can cause a number of side effects that range from mild to serious. However, most are temporary and go away after a few days to weeks. If you have questions about side effects that Dulera can cause, talk with your doctor.

Examples of questions to help get you started include:

  • What are my risks of developing side effects from Dulera?
  • Will I have withdrawal side effects if I suddenly stop Dulera?
  • What should I do to avoid developing an infection while taking Dulera?

To learn more about Dulera, see these articles:

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Disclaimer: Healthline 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.