Dulera (mometasone furoate and formoterol)

Dulera (mometasone furoate and formoterol) is a combination inhaler that has an inhaled corticosteroid and a long-acting beta-agonist (abbreviated: LABA). Dulera is approved for the treatment of asthma in people ages 5 years and older. It is made by Merck & Co. Dulera comes as a metered dose inhaler.1

Do not take Dulera if you are having an asthma attack. It does not work quickly enough. Use a rescue inhaler (short-acting beta agonist) instead.

How does Dulera work?

Dulera contains two medications. Mometasone furoate is an inhaled corticosteroid.1 This medication reduces inflammation in the airways. Corticosteroids affect many different types of inflammatory cells, including eosinophils and mast cells. They also affect signaling chemicals that have a role in inflammation such as histamine, leukotrienes, and cytokines.

Formoterol is a LABA.1 This medication relaxes the muscles that surround the airways. This helps the airways to open up. Formoterol also prevents mast cells from sending out chemical signals that increase inflammation. This makes the airways less sensitive (“hyperresponsive”).

How is a Dulera inhaler used?

Ask your health care provider or respiratory therapist to show you how to use your inhaler properly.

Dulera is a blue metered-dose inhaler.1 It comes in three strengths: 50 mcg, 100 mcg, and 200 mcg mometasone furoate, each combined with 5 mcg formoterol. The usual dose is two puffs twice per day: once in the morning and once in the evening (Table).2

Before using the inhaler for the first time, you have to prime it.2 To prime the inhaler, shake it well. Turn the inhaler away from you and press the canister down, releasing one puff into the air. Shake and spray your inhaler three more times. You have to prime it again if you have not used the inhaler for five days.

Table. Using your Dulera metered dose inhaler

The steps for using your Dulera metered dose inhaler are:

  1. Shake the inhaler.
  2. Breathe out until your lungs are empty.
  3. Put the mouthpiece in your mouth and close your lips around it.
  4. Begin to breathe in deeply and slowly through your mouth. Push the canister down to release a "puff" as you breathe in. Once you have pushed the canister all the way down, lift your finger off the canister.
  5. After you have inhaled fully, hold your breath for 10 seconds.
  6. Remove the inhaler from your mouth. Breathe out slowly through your nose, keeping your lips shut.
  7. Wait 30 seconds. Shake the inhaler again and repeat steps 1 through 6.
  8. Rinse your mouth with water and spit out the water. This step will help to prevent thrush, a fungal infection of the mouth.


  • Read the Patient Information that comes with your inhaler for complete instructions.
  • The inhaler is best used at room temperature.
  • You can use a spacer or valved holding chamber with a metered dose inhaler. These devices help the medications to get into your lungs.

Dulera [patient information]. Whitehouse Station, NJ: Merck & Co; 2010.

Recommendations for storing, cleaning, and discarding Dulera

Dulera comes in a blue plastic inhaler with a separate metal canister containing the medication.2  Do not use the Dulera inhaler with other medications. Do not use other inhalers with the Dulera canister.

Do not remove the canister from the inhaler.2 If you do, the counter may not work correctly. Once a week, wipe the mouthpiece and outside with a clean dry tissue.2

Throw away the canister and inhaler when the counter reads 0.1 You have used all the medication. Store your Dulera at room temperature (68˚F and 77˚F). Avoid high heat or flames.

Risks of taking Dulera

One of the medications in the Dulera inhaler is formoterol, a LABA. In large studies, people who took a different LABA called salmeterol had an increased risk of asthma-related death.1 In these studies, there were 13 deaths out of 13,176 people who took salmeterol, compared with 3 deaths out of 13,179 people who took a fake medication (placebo). Children and adolescents who take LABAs have a higher risk of hospitalization.

The US Food and Drug Administration says that LABAs should only be used with second medication, such as an inhaled corticosteroid.3 Dulera contains both a LABA and an inhaled corticosteroid. Trials are underway to study LABAs as part of a combination treatment.4 Currently, it is not known whether taking a LABA with an inhaled corticosteroid decreases the risk of asthma-related death.1

Possible side effects of taking Dulera

Taking Dulera could cause your airways to tighten suddenly (“bronchospasm”).1 This side effect can happen right after using the inhaler. Take your rescue inhaler and call your health care provider.

Common side effects of Dulera are headache and inflammation of the nose, throat, and sinuses.2 Using too much formoterol, one of the medications in Dulera, can cause increased heart rate, high blood pressure, chest pain, headache, dizziness, weakness, tremor, or nervousness.2 This is not an exhaustive list of side effects.

Inhaled corticosteroids such as mometasone furoate can cause thrush, a fungal infection in your mouth.2 You can help to prevent this by rinsing your mouth with water after using the inhaler and spitting out the water.

Corticosteroids can lower your immune system, so you are more likely to get an infection.2 Symptoms of an infection are fever, pain, aches, chills, fatigue, nausea, or vomiting. Avoid contact with people who have chicken pox, measles, or other contagious diseases.1 Tell your provider if you have any infections, including tuberculosis or herpes simplex of the eye.1

Children who use corticosteroids may grow more slowly.2 Your child’s growth should be checked regularly.

People who should not take Dulera

People taking another LABA should not take Dulera.2 If your asthma can be controlled with a low- or medium-dose inhaled corticosteroid alone, you also should not take Dulera.1

Tell your health care provider if you have had problems with your heart, eyes, immune system, thyroid, or liver.2 You should also tell your provider if you have high blood pressure, seizures, diabetes, osteoporosis, an aneurysm, or adrenal gland tumor. Taking corticosteroids or LABAs may worsen these conditions. Extra monitoring or an alternative treatment may be needed. Tell your health care provider if you are scheduled to have surgery. Tell your health care provider about any prescription medications you take, particularly LABAs, oral corticosteroids, antifungals, or anti-HIV medications. Let your provider know about over-the-counter medications or supplements that you take.

Dulera has not been well studied in pregnant or breastfeeding women.2 Little is known about whether this medication passes into breast milk. Talk to your doctor about if you become pregnant or wish to breastfeed while taking Dulera.

If you are allergic to any ingredient in Dulera, you should not take this medication.2

Is there a generic alternative to a Dulera inhaler?

There is no generic alternative to Dulera. The two medications in Dulera are available separately.

Mometasone furoate is marketed as Asmanex. It is available in generic form to treat asthma.

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Written by: Sarah O'Brien | Last Reviewed: April 2021.