What is Asmanex twisthaler (Mometasone furoate)?

Asmanex is an inhaled corticosteroid used by adults and children with asthma. It is used on a regular basis to try and reduce the number and frequency of asthma attacks. This is known as asthma prophylaxis.

Asmanex Twisthaler

Prescription Required.

Product of Canada.

Shipped from Canada.

Prescription Required.Product of Canada.Shipped from Canada.

What is Asmanex twisthaler (Mometasone furoate)?

Asmanex is an inhaled corticosteroid used by adults and children with asthma. It is used on a regular basis to try and reduce the number and frequency of asthma attacks. This is known as asthma prophylaxis.

How does it work?

Asmanex is a steroid medication which works by reducing inflammation in the lungs as this can trigger asthma attacks. It is commonly referred to as a “preventer” medicine. It will not help to treat wheezing or breathlessness during an active asthma attack as other inhalers do. It is important to use Asmanex regularly to benefit from its effects.


100 µg/ inhalation

Each metered inhalation contains 100 µg of mometasone furoate. The nonmedicinal ingredients include lactose anhydrous.

200 µg/ inhalation

Each metered inhalation contains 200 µg of mometasone furoate. The nonmedicinal ingredients include lactose anhydrous.

400 µg/ inhalation

Each metered inhalation contains 400 µg of mometasone furoate. The nonmedicinal ingredients include lactose anhydrous.

How to use

As Asmanex works in the lungs, it must be inhaled to be effective. It comes as a plastic inhaler device with dry powder medicine inside.

To use your twisthaler:

  • Start by holding the device straight up
  • Twist off the cap to remove. This action should activate the device for use
  • Breathe out as far as you can
  • Place the mouthpiece between your lips, forming a tight seal
  • Take a deep breath in to ensure all of the medicine reaches your lungs
  • Take the twisthaler out of your mouth. Close your mouth and hold your breath for 10 seconds
  • After this you can breathe normally
  • Close the device by replacing the cap
  • If your doctor has recommended more than one puff, leave one minute between doses, breathing normally
  • It is advised that you rinse your mouth out with water or clean your teeth after use to reduce the risk of developing oral thrush

The advice above is the same for adults and children. A younger child may need help using the twisthaler device.

If you are not sure about any of the above steps, speak with your doctor or healthcare professional. It is important that Asmanex is administered properly in order for it to work.


This medicine should be kept away from heat and direct sunlight. It should be kept out of the reach of children.


For children between the ages of 4 to 11, the typical recommended dose is 100 µg to be inhaled orally, once daily each evening.

For adults and children over the age of 12, the typical recommended dose is 200 µg to 400 inhaled orally, once daily each evening.

Patients who have been using high doses of inhaled steroids may respond more positively to 200 µg inhaled twice daily. 800 µg is the maximum dose each day.

Depending on how well Asmanex Twisthaler is working for the patient, their doctor may either increase or decrease the dose. Once the patient’s breathing has improved, the dose should be kept as low as possible to keep the patient’s asthma under control. If a patient’s asthma symptoms become worse while using mometasone furoate, their doctor may increase their dose or instruct them to use it more often.

Patients should follow the instructions to use the inhaler correctly. If they have any concerns, they should ask their doctor or pharmacist. Patients may not be able to sense the powder entering their mouth or their lungs as it will be difficult to detect such a small amount of powder in each dose.

If the patient’s doctor advises them to stop taking Asmanex Twisthaler, they should not suddenly stop using it. Instead, they should gradually taper off to avoid exacerbating the symptoms.

To help avoid developing a yeast infection (thrush) in the mouth, patients should rinse their mouth and gargle after each inhalation.

Asmanex Twisthaler will not help to relieve the effects of an asthma attack that is already in progress. Mometasone furoate is meant to help to prevent asthma symptoms. Patients should not use Asmanex Twisthaler when experiencing an asthma attack. Instead, patients should use their “reliever” medication, such as salbutamol or terbutaline. It will be necessary to use these fast-action medications with mometasone furoate.

Side Effects

Some people may experience an allergic reaction to Asmanex. Stop taking medication immediately and seek medical attention if you experience signs of a severe allergic reaction. Typically, this would manifest as hives, difficulty breathing and/or swelling of the face or throat.

Skin reactions can occur in some people using Asmanex. Stop taking medication immediately and seek medical attention if you experience signs of a skin reaction. This would include blistering, peeling of skin, or a rash that covers a large area, spreads quickly or is associated with a fever.

Common side effects typically affect 5-10% of people using Asmanex include headache, oral thrush, altered taste, and changes to your voice.

Uncommon side effects, reported in approximately 1-5% of those using include anxiety, paradoxical bronchospasm, cataract, blurred vision.

Rare side effects seen in <1% of people include adrenal suppression, abnormal behaviour, glaucoma, growth retardation in children, sleep disorder.

If you have chronic obstructive pulmonary disorder (COPD), Asmanex could put you at higher risk of pneumonia.

Systemic absorption may follow inhaled administration, particularly if high doses or prolonged treatment is used.

You may experience hoarse voice after using, rinsing your mouth with water should help reduce this. If you find that you have a dry mouth, eating citrus fruits or sipping water may help.

The risk of oral thrush, or candidiasis can be reduced by using a spacer device with your inhaler.  You should try rinsing your mouth with water after using your inhaler as this can also reduce the risk of developing oral thrush. Oral candidiasis can be treated without stopping use of your inhaler. Anti-fungal oral suspensions or gels can be used alongside your inhaler.

When used in high doses Asmanex can cause adrenal insufficiency. This means that the adrenal glands are producing less hormones than usual. Cortisol is one such hormone. Low levels of cortisol may cause difficulty in fighting off infection or recovering from injury. If you are concerned speak with your doctor.

You may experience withdrawal symptoms if you stop or reduce your dose of Asmanex. These may include feeling dizzy, tired, experiencing stomach pains or vomiting. If this occurs, contact your doctor as soon as possible. You should not alter your dose or stop medication without first discussing this with your doctor.

An inhaled steroid could reduce your bone density which can lead to fractures or osteoporosis. Your doctor may ask you questions related to this and may send you for a bone scan.

You may experience side effects other than those listed above. Always check with your doctor if you are concerned.

If patients are concerned about side effects after taking this medication, they should discuss the possible risks and potential benefits with their doctor. Many of these side effects may disappear over time or can be managed. A pharmacist should be able to make recommendations for managing these side effects. However, the patient should contact their doctor if the side effects become severe or significantly uncomfortable.

Not everyone who takes this medication will experience side effects. However, at least 1% of people taking this medication have experienced the side effects listed below.

  • burning or painful sensation on the tongue
  • constipation
  • decreased appetite
  • diarrhea
  • dizziness
  • dry mouth or throat
  • ear pain
  • fatigue
  • headache
  • hoarseness or loss of voice
  • increased saliva production
  • increased sweating
  • muscle and joint pain or stiffness
  • nasal congestion
  • nausea
  • sore throat or mouth
  • red or itchy eyes
  • stomach ache
  • thirst
  • upset stomach
  • vomiting

More serious side effects

These serious side effects are rare but can cause severe issues if they are not addressed. If a patient experiences any of these, they should see their doctor as soon as possible.

  • cough
  • fever
  • irregular menstrual bleeding
  • migraine
  • osteoporosis or bone fractures
  • pins and needles or numb arms or legs, sinus pain and congestion, worsening breathing problems (Churg-Strauss Syndrome)
  • signs of depression, such as:
    • poor concentration
    • changes in weight
    • changes in sleep
    • decreased interest in activities
    • thoughts of suicide
  • signs of clotting problems, such as:
    • unusual nosebleeds
    • bruising
    • blood in urine
    • coughing blood
    • bleeding gums
    • cuts that don’t stop bleeding
  • signs of liver problems, such as:
    • nausea
    • vomiting
    • diarrhea
    • loss of appetite
    • weight loss
    • yellowing skin or eyes
    • dark urine
    • pale stools
  • signs of respiratory tract infection, such as:
    • fever or chills
    • shortness of breath
    • prolonged dizziness
    • headache
    • weight loss
    • tightness in chest
    • difficulty breathing
    • wheezing
  • skin issues, such as:
    • rash
    • hives
    • chafing
    • itching
    • bruising
  • slowed growth in children and adolescents
  • symptoms of adrenal insufficiency, such as:
    • tiredness
    • headache
    • nausea
    • vomiting
    • muscle or joint pain
  • symptoms of glaucoma or cataracts, such as:
    • blurred vision
    • seeing circles of bright colors around lights
    • red eyes
    • increased pressure in your eyes
    • eye pain or discomfort
  • wheezing or difficulty breathing right after inhaling the medication
  • white fungal infection patches in the mouth or throat
  • worsening asthma

Side effects requiring urgent medical attention

Patients experiencing any of the following side effects should discontinue treatment and immediately seek the attention of a medical professional.

  • chest pain
  • increased heart rate
  • severe allergic reaction, such as:
    • hives
    • difficulty breathing
    • swelling of the face
    • mouth or tongue
  • worsening asthma or sudden asthma attacks with symptoms such as:
    • cough
    • difficulty breathing
    • wheezing

It is possible to experience side effects other than those listed above. Patients should discuss with their doctor any symptoms that worry them.

Warnings & Precautions

Before taking any medication, patients should always check the ingredients for anything they may be allergic to. They should not take this medication if they are allergic to it or any of its ingredients.

The patient’s medical conditions or allergies may impact whether or not their doctor may recommend this medication.

Patients should not take this medication if they:

  • are allergic to mometasone or any of its ingredients
  • are allergic to milk or lactose
  • are experiencing an asthma attack
  • have active or inactive lung tuberculosis
  • have an untreated fungal, bacterial, or viral lung infection
  • have herpes simplex infection of the eye
  • have status asthmaticus (severe, unresponsive asthma)


Interactions are less common with inhaled steroids than those taken orally. If in doubt, check with your doctor pharmacist. Medications known to interact with Asmanex:

  • Aceclofenac
  • Acenocoumarol
  • Aspirin
  • Atazanavir
  • Atracurium
  • Bacillus Calmette-Guerin (BCG) vaccine
  • Benzydamine
  • Bromfenac
  • Celecoxib
  • Choline salicylate
  • Cisatracurium
  • Clarithromycin
  • Cobicistat
  • Darunavir
  • Deferasirox
  • Dexketoprofen
  • Diclofenac
  • Dinutuximab
  • Erlotinib
  • Etodolac
  • Etoricoxib
  • Felbinac
  • Flurbiprofen
  • Fosamprenavir
  • Glycerol phenylbutyrate
  • Herpes-zoster live vaccine
  • Ibuprofen
  • Idelalisib
  • Indometacin
  • Influenza live vaccine
  • Itraconazole
  • Ketoconazole
  • Ketoprofen
  • Ketorolac
  • Lopinavir
  • Measles, mumps, rubella live vaccine
  • Mefenamic acid
  • Meloxicam
  • Mifamurtide
  • Mifepristone
  • Mivacurium
  • Nabumetone
  • Naproxen
  • Nepafenac
  • Nicorandil
  • Nirmatrelvir
  • Pancuronium
  • Parecoxib
  • Phenazone
  • Phenindione
  • Piroxicam
  • Ritonavir
  • Rocuronium
  • Rotavirus vaccine
  • Sodium phenylbutyrate
  • Somatrogon
  • Somatropin
  • Sulindac
  • Suxamethonium
  • Tenoxicam
  • Tiaprofenic acid
  • Tipranavir
  • Tolfenamic acid
  • Typhoid vaccine – oral
  • Varicella zoster vaccine
  • Vecuronium
  • Voriconazole
  • Warfarin
  • Yellow fever vaccine

If you are on any of the medications mentioned above consult with your doctor or your pharmacist. It may be necessary to stop taking one of the medications; change one of the medications to an alternative; change how or when you take one or both medications; or your healthcare professional may decide it is best to leave all medications as they are.

The list above may not contain all medications known to interact with Asmanex. It is important that you inform your doctor of all medications, herbal medications, supplements, over the counter medication and recreational drugs that you are taking.


A severe overdose of mometasone furoate could lead to symptoms of hypercorticism.

If the patient or anyone else has overdosed on mometasone furoate, a doctor should be contacted. If someone has collapsed or is no longer breathing after using the medication, emergency services should be contacted.

Frequently Asked Questions

Asmanex is a brand of the medication mometasone furoate. This is a corticosteroid that is administered by an inhaler device containing a powdered form of the active drug. It can reduce the number and frequency of asthma attacks.

The inhaler device ensures that the  medication is administered directly to the lungs. It works to reduce swelling and inflammation in the small passages and air sacs in your lungs to make breathing easier. It is commonly known as a “preventer” medication. See above for instructions on how to use your inhaler.

Asmanex comes as a 110mcg or 220mcg inhalers. Depending on your age and the treatments you have received in the past, your doctor will decide on the dose you receive. It can be prescribed as one puff or two puffs and also as once or twice per day.

Asmanex works to reduce the number of asthma attacks that you experience. It is not a bronchodilator and should not be used as a “rescue” inhaler during asthma attacks or when you feel short of breath.

Inhaled steroid medications can cause fungal infections of the mouth or oral thrush. Rinsing your mouth after use should help to decrease the chances of this occurring.

Asmanex should be stored in a clean and dry place, out of the reach of children. If you need to clean the mouthpiece of your inhaler, do so with a dry cloth or tissue. Do not wash your inhaler.

Asmanex will start working within 24 hours, however it may be several weeks before there is a noticeable difference on the inflammation in your lungs. You may still experience asthma attacks during these first few weeks. You should continue to use your inhaler as prescribed by your doctor even if you are not seeing improvement.

This medication can be used in children over the age of 4. Your child’s height and weight will be monitored regularly while using Asmanex. There is a small chance that growth could be slowed in children using this medicine. Usually, your child will catch up to their peers once their asthma is under control. It should not affect their final adult height. If you are concerned, you can discuss this with your doctor.

You should continue to take Asmanex as prescribed unless told otherwise by your doctor. It is likely that you will need to use this medicine long term.

There are other medications which can help to manage asthma. There are other inhalers and oral medications that may be helpful. This is best discussed with your doctor who can help to make the right choice of medication for you.

Asmanex is a corticosteroid medicine. This should not be confused with anabolic steroids which are sometimes misused by athletes and bodybuilders. Asmanex is used to treat asthma as it works as an anti-inflammatory agent, reducing inflammation in the lungs.

Yes. Asmanex can be used as prescribed during pregnancy or as directed by your physician.

Yes. Asmanex can be used as prescribed if breastfeeding.

Asmanex usually provides benefit for a 24-hour period. Therefore, you should take your inhaler regularly, every day as prescribed by your doctor.

If you take Asmanex twice per day, you can take a forgotten or missed dose up to 4 hours after the scheduled time. If it is more than 4 hours since you were due to take your dose, do not take your missed dose and continue with your prescribed schedule for the medication.

Never give a double dose of Asmanex unless advised by your doctor to do so.

It is unlikely that you will experience any complications by taking extra Asmanex. It is not advised to take extra doses unless advised to by a doctor. If you are concerned that you may have taken extra medication, contact your doctor or healthcare professional as soon as possible.

After several weeks you should notice a reduction in the number asthma attacks that you experience. If there is no change after a few weeks of using Asmanex as prescribed contact your doctor for advice.

This is a prescription medicine. Do not give to others even if they have similar symptoms. Consult your doctor before starting or stopping any medications.

If you have any questions or concerns regarding use of this medication you can discuss these with your doctor, pharmacist, or healthcare provider.