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Also known as Mannitol Challenge Test

Duration: 60 minutes


  • You may be advised by your Doctor to stop some regular medications

  • 72 hours (3 days) before the test, stop any antihistamine medication. 

  • 24 hours before the test stop taking any of the following inhalers: serevent, seretide, symbicort, oxis, foradil or fostair. (Medications for Asthma or COPD)

  • on day of test: avoid caffeine products (coffee, tea, energy drinks, smoking and strenuous exercise 

  • If you are positive for asthma, it may trigger symptoms, best to have someone who can drive accompany you to your appointment

What does the test involve? 

You will be seated comfortably in a chair. During the test  a highly trained respiratory scientist will ask you to inhale some Mannitol – which is a sugary powder. Between doses you will perform spirometry (a simple breathing test) to assess how your lungs respond to the Mannitol.

Are there any risks?

This test does not cause an asthma attack but the inhalation of the Mannitol for people who do have airway sensitivity their airways will become narrower and so they may find it harder to breathe.

Some patients may experience symptoms of cough, chest tightness, wheezing, chest soreness or headache.  Many subjects do not have symptoms at all. These symptoms (if they occur) are mild, last for only a few minutes, and disappear following the inhalation of a bronchodilator medication.

How much does it cost?

Patients can enquire about the cost of the test when making an appointment. 

If you have any of the following please call us to discuss:

  • Unstable angina

  • A recent pneumothorax (air trapped beneath the chest wall)

  • A recent heart attack or stroke

  • Recent eye or abdominal surgery

  • Coughed up blood recently and the cause is not known

  • Known hypersensitivity to mannitol or gelatin used to make capsules

  • Conditions that may be compromised by induced bronchospasm or repeated spirometry maneuvers

  • High blood pressure

  • Pregnancy

  • Nursing mothers Patients 6-18 years of age, due to limited information on the use of Osmohale in this population.

What happens after the test? The results will be sent to the Doctor that requested the test and they will discuss the results with you at your next appointment.

What is Bronchoprovocation Challenge Test?

Bronchoprovocation Challenge test is the most modern test of bronchial reactivity which is less prone to false negative results than other traditional bronchial challenge tests. Bronchial provocation tests are commonly performed to assist with the diagnosis and treatment of asthma.

Increasing doses of a simple sugar (mannitol) impregnated with a dehydrating agent are inhaled at specific intervals and are intended to mimic the effects of physical exercise on the airways. Dehydration of the airways in this way will trigger a cascade of physiological processes which cause the smooth muscle in the bronchial airways to contract, akin to the effects of asthma.

Spirometric measurements are conducted after each dose inhalation to gauge airway constriction. A positive response is suggestive of active airway inflammation and airway hyperresponsiveness that isconsistent with a diagnosis of asthma.

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