What to Know About Asmanex HFA and Twisthaler (Mometasone Furoate)

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Mometasone furoate is a prescription steroid inhaler used daily as a controller medication for preventing asthma symptoms. It is marketed under the brand names Asmanex HFA and Asmanex Twisthaler; there is no generic. Mometasone furoate is also available in Dulera, a combination asthma inhaler.

Mometasone furoate, like most steroids, reduces inflammation. Because it is an inhaled medication, it directly targets the airways in the lungs. This anti-inflammatory effect helps decrease lung hyperresponsiveness, which plays a role in asthma symptoms.

Young woman using inhaler

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Mometasone furoate can be used for mild, moderate, or severe forms of asthma. The purpose of this medication is to reduce asthma symptoms and asthma attacks, and to decrease your need for a rescue inhaler.

Asthma controllers are medications that are used on a regularly scheduled basis for the prevention of asthma symptoms and asthma attacks. There are several types of asthma controllers, including inhaled steroids like mometasone furoate.

Mometasone furoate is not available in generic form. The two available brand-name forms—Asmanex Twisthaler and Asmanex HFA— can be prescribed alone, or you might also receive a prescription for a long-acting beta-agonist (LABA) bronchodilator such as formoterol. Narrowing of the airways and inflammation both contribute to asthma symptoms, and the addition of a LABA can help keep airways open.

Dulera (mometasone furoate and formoterol fumarate dihydrate) includes both mometasone furoate and formoterol.

While not used for asthma, Nasonex nasal spray—a prescription medication used for the prevention of allergic rhinitis—contains mometasone furoate monohydrate.

Mometasone furoate isn't typically used off-label.

Before Using

Your healthcare provider may consider prescribing mometasone furoate for you if you have recurrent asthma symptoms—wheezing, chest tightness, cough, shortness of breath—or need to frequently use a rescue medication.

The effects of this medication on pregnant and nursing mothers and their babies are not well known. So you and your healthcare provider will have to talk about the risks if you are taking mometasone furoate and are pregnant or plan to become pregnant or breastfeed.

Precautions and Contraindications

Mometasone furoate should not be used as a rescue inhaler or to treat asthma symptoms after they have already started, as it is ineffective for these purposes. This goes for all of its available forms, even the combination inhaler.

The drug is approved for use in adults and children, but only of a certain age:

  • Asmanex Twisthaler is approved for adults and children age 4 and older.
  • Asmanex HFA and Dulera are approved for adults and children age 12 and older.

You should not use mometasone furoate if you have ever had an allergic reaction to any of its formulations.

Because this medication can suppress the immune system and increase the risk of cataracts, glaucoma, and bone thinning, it should be used with caution if you already have any of these conditions or severe bone thinning due to osteoporosis.


When you take mometasone furoate, it's important that you use your inhaler on a daily basis. The anti-inflammatory effect of this steroid involves a process that doesn't work immediately, so you might not notice any improvement of symptoms until several weeks after you've started using it every day.

Your starting dose is based on the manufacturer's recommendations, and your healthcare provider may make adjustments based on your disease severity, other asthma therapies, and previous response to other asthma therapies.

Medication Available Doses Recommendations
Asmanex HFA 100 micrograms (mcg) or 200 mcg Two inhalations of 100 mcg or 200 mcg twice daily (a.m./p.m.)
Asmanex Twisthaler 110 mcg or 220 mcg Age 12+: One 220-mcg inhalation per day (p.m.)
Ages 4-11: 110 mcg once per day (p.m.)
Dulera 100 or 200 mcg
Both combined with 5 mcg formoterol fumarate per actuation
Two inhalations of 100 mcg/5 mcg or 200 mcg/5 mcg twice daily (a.m./p.m.)

Dosages are for adults and children 12 and older, unless otherwise noted. Speak to your healthcare provider about the correct dose for you or your child.


You may need a lower dose prescription of this medication if you have liver disease.

If you or your child are temporarily taking a prescription of oral steroids for worsening asthma symptoms, your healthcare provider might prescribe a short course of higher dose of Asmanex Twisthaler for a couple of weeks until symptoms improve.

How to Take and Store

When using an inhaler, you need to make sure to get the timing and technique right. For mometasone furoate inhalers, you will need to:

  1. Exhale fully.
  2. Place your mouth tightly around the mouthpiece.
  3. Press on the inhaler to release the medication as you inhale deeply.
  4. Hold your breath for 10 seconds before exhaling.
  5. Breathe deeply and slowly for a few minutes.
  6. Repeat again if you need to take two inhalations per dose.
  7. Clean your inhaler by wiping the mouthpiece with a dry cloth after each use.

You should make sure that your pharmacist or someone from the medical team at your healthcare provider's office observes your technique before you start regularly taking your medication to make sure you have the hang of it. And don't hesitate to ask for help—using an inhaler isn't intuitive and you want to make sure you are getting the intended effects of your treatment.

Asmanex Twisthaler, Asmanex HFA, and Dulera should be stored at room temperature (between 68 to 77 degrees F) and away from heat and moisture.
Any expired product should be discarded.

Side Effects

Mometasone furoate is generally well tolerated. However, it can cause certain side effects.


Steroids, including mometasone furoate, can increase the risk of some infections due to a reduction in immune activity. The most frequently seen side effects of mometasone furoate are mild infections.

Common side effects include:


This drug can also cause severe systemic side effects, although these issues are rare. An anaphylactic reaction can develop quickly and may be life-threatening.

Signs of an anaphylactic reaction include:

  • Hives
  • Rash
  • Swelling of the face and mouth
  • Difficulty breathing

And less commonly, this medication can paradoxically induce severe asthma symptoms due to bronchospasm. If you develop trouble breathing, wheezing, or chest tightness, get medical attention right away.

Because it suppresses the immune system, mometasone furoate can induce reactivation of a severe infection, such as tuberculosis, a parasitic infection, or chickenpox. Signs of these infections can worsen over the course of days or weeks. Call your healthcare provider if you experience fevers, fatigue, muscle aches, or any other new symptoms.

If you take mometasone furoate, it's important that you see your healthcare provider regularly. Even if your asthma is well controlled, you need to be screened for possible side effects.

Delayed Effects

You can have a higher risk of cataracts or glaucoma when taking mometasone furoate. These eye problems don't normally cause symptoms at early stages, and they can be identified with an eye examination.

Hormonal changes can occur when taking mometasone furoate, and this may cause a variety of effects, including bone thinning in children and adults. Menstrual irregularities can occur as well.

Additionally, adrenal gland function can be impaired—with an increase or a decrease of adrenal hormones. This can cause subtle symptoms like fatigue or increased or decreased urination.

Children may develop alterations in growth hormone, which can result in slow or delayed growth. Parents should watch for signs of slow growth or any other side effects, as children might be unlikely to notice them should they occur.

Warnings and Interactions

Mometasone furoate does not have major drug interactions. If you take a medication that's metabolized by the cytochrome P450 system, such as ritonavir (used for the treatment of HIV) or ketoconazole (an antifungal medication), you may have an elevated concentration of mometasone furoate.

This doesn't mean that you can't take mometasone furoate if you are taking other medications that could interact with it—just that your healthcare provider and pharmacist might recommend dosing adjustments to make sure you are getting the right amount of medication.

A Word From Verywell

Asthma controllers are an essential part of asthma management if you have recurrent symptoms. As with other steroid asthma controllers, mometasone furoate is intended to keep you from having frequent asthma symptoms and from relying on rescue inhalers too often.

If you are taking mometasone furoate, either on its own or as part of a combination prescription, try to keep track of the severity and frequency of your asthma symptoms and let your healthcare provider know if you experience any changes. They could be an indication for a change in your asthma medication regimen.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Passali D, Spinosi MC, Crisanti A, Bellussi LM. Mometasone furoate nasal spray: a systematic review. Multidiscip Respir Med. 2016;11:18.doi:10.1186/s40248-016-0054-3

  2. Weinstein CLJ, Ryan N, Shekar T, et al. Serious asthma events with mometasone furoate plus formoterol compared with mometasone furoate. J Allergy Clin Immunol. 2019;143(4):1395-1402.doi:10.1016/j.jaci.2018.10.065

  3. Food and Drug Administration. Nasonex (mometasone furoate monohydrate) label.

  4. Food and Drug Administration. Asmanex Twisthaler (mometasone furoate inhalation powder) label.

  5. Food and Drug Administration. Asmanex HFA (mometasone furoate) inhalation aerosol label.

  6. Prescribers' Digital Reference. Mometasone furoate-drug summary.

  7. Lei J, Ma S. Mometasone furoate for children with asthma: A meta-analysis. Am J Emerg Med. 2020;Feb 24.doi:10.1016/j.ajem.2020.02.052

By Pat Bass, MD
Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians.