Mannitol (Inhalation)

As a diuretic, mannitol is used by healthcare professionals to diagnose asthma, the results are received right away.


Mannitol belongs to the group of medicines known as diuretics. The prescription medication is commonly used as a diagnostic test for asthma in a procedure known as the bronchial challenge test. Healthcare professionals use the medicine to determine whether or not their patients experience difficulty in breathing. Before using the medication, you should alert your doctor if you have an allergy to mannitol or its other components. In addition, do not use the medication if you have a serious or chronic kidney condition or you are suffering from swollen or congested lungs. Studies also reveal that mannitol should not be used by any child younger than six years of age.

The dosage given depends on several factors such as the patient's medical history, other medical conditions, and responsiveness. You should not use mannitol if you have any kind of heart disease or a history of kidney illness to avoid the occurrence of harmful side effects. Electrolyte imbalance, such as low magnesium or potassium levels, may cause the results to be inaccurate. According to the FDA, the effects of the drug on a fetus are unknown, so consult a healthcare provider if you are pregnant or planning to conceive soon after using the medication.

The medicine is given in a hospital setting through the inhalation route. Since you will be monitored by a healthcare professional, it is unlikely that you will miss a dose or overdose on the medicine. Always follow the instructions given by your healthcare provider with regards to the activities, beverages, or foods that are prohibited.

Tell your doctor if you are using any other prescription medication, herbal products, and supplements to prevent possible interactions from occurring. Mannitol may also interact with alcohol and street drugs.

Conditions Treated

  • Asthma diagnosis

Type Of Medicine

  • Diuretic

Side Effects

Mannitol causes several side effects while delivering its needed effects. Not all of the described effects may occur, but if you identify any of them, contact your doctor. Some common symptoms that are serious include the following:

  • Coughing
  • Dry heaves
  • Difficulty in breathing
  • Chest discomfort
  • Chest tightness
  • Wheezing
  • Runny nose
  • Gagging
  • Chronic migraines
  • Dry mouth
  • Excessive dehydration
  • Excess urination
  • Vision problems
  • Chills or fever
  • Confusion
  • Swelling of tongue, lips, or face
  • Itching
  • Swelling of ankles, knees, or feet
  • Seizures
  • Muscle pain
  • Unusual fatigue

Other side effects that might occur may not be serious because they are usually a reaction of your body to the drugs. After the body adjusts to the medicine, these symptoms often disappear. Consult your healthcare provider to learn how to minimize or prevent these effects. On the other hand, it is advisable to seek medical assistance if the following symptoms do not disappear after a few days:

Some patients have reported rare side effects. These include the following:

  • Blood clots in veins
  • Acidosis
  • Painful or difficult urination
  • Inability to empty bladder
  • Low blood pressure
  • Fast heartbeat
  • High blood pressure
  • Body fluid imbalance
  • Kidney failure
  • Skin inflammation
  • Lung congestion
  • Back pain
  • Nose inflammation
  • Rapid weight gain

There are several other side effects that may not be listed in this guide. Discuss with your healthcare provider in case you exhibit other rare symptoms.


The mannitol test kit contains an inhaler (for one patient, for single use only) and three blister packs, which contain 19 mannitol capsules that will be used for inhalation. The dose dose is administered sequentially by increasing it while measuring the forced expiratory volume released in a second (FEV1). A positive response entails the FEV1 reduction of 15%.

The initial dose will be increased until the required response is achieved or when a cumulative dose of 635 mg has been administered with no response, which constitutes a negative test. The sequential doses are as follows:

  • Dose number 1: 0 mg (one capsule per dose with a 0 mg cumulative dose)
  • Dose number 2: 5 mg (one capsule per dose with a 5 mg cumulative dose)
  • Dose number 3: 10 mg (one capsule per dose with a 15 mg cumulative dose)
  • Dose number 4: 20 mg (one capsule per dose with a 35 mg cumulative dose)
  • Dose number 5: 40 mg (one capsule per dose with a 75 mg cumulative dose)
  • Dose number 6: 80 mg (two 40 mg capsules with a 155 mg cumulative dose)
  • Dose number 7: 160 mg (four 40 mg capsules with a 315 mg cumulative dose); this dose may be repeated two more times if desired response is not observed for a a 635 mg cumulative dose
  • Dose number 8: 160 mg (four 40 mg capsules with a 475 mg cumulative dose)
  • Dose number 9: 160 mg (four 40 mg capsules with a 635 mg cumulative dose)

When given the capsules, do not put them in your mouth; they should not be swallowed. The test is performed as described below:

  • First of all, you should ask your doctor to perform a spirometry test (lung or breathing test) before you proceed to the bronchial challenge test.
  • A nose clip will be placed on your nose, which means that you will be breathing through your mouth.
  • Put the 0 mg capsule inside the inhaler and puncture it by pressing the two buttons located at the sides of the inhaler.
  • Place the inhaler right in front of your mouth; let out as much air as you can by breathing out fully before you inhale, which is the best way of inhaling as much of the medicine as possible.
  • Breath in deeply and slowly (like you are yawning) to inhale the medicine.
  • Hold your breath for approximately five seconds, and then breathe out prior to removing the nose clip.
  • The steps will be repeated a total of nine times, so that the effects of mannitol on your lungs can be measured.
  • For the patients with a positive result (which means that they have asthma), they will be given a short-acting inhaler.
  • Discard the inhaler immediately after using it.


When a medicine is used together with other types of drugs, interactions may occur, which may cause severe side effects at times. Mannitol may interact with other drugs, including dietary, recreational, prescription, herbal, nutritional, illegal, and non-prescription. Some of the over-the-counter medications that may interact with mannitol include the following:

  • Medication for depression such as Effexor, Lexapro, or Cymbalta
  • Drugs for heartburn, such as Dexilant, Protonix, or Nexium
  • Medicine for diabetes, such as Tanzeum, Byetta, or Bydureon
  • Any medication that contains either Farxiga, Xigduo XR, dapagliflozin, Invokamet, Invokana, or canagliflozin
  • Drugs for bowel preparations such sodium sulfate or phosphate
  • Lithobid
  • Tobi Podhaler
  • Minitran
  • Nitrostat
  • Nitromist
  • Natrecor
  • Rectiv

Mannitol also interacts with alcohol and can cause excessive thirst, frequent urination, and dehydration. Since it is not possible to know whether or not a healthcare provider will treat you with mannitol, it's recommended to limit alcohol intake when you start exhibiting the symptoms described.


This diagnostic test may be affected by the presence of other medical conditions, so precaution must be observed. Consult your doctor in case you are suffering from the following illnesses:

  • Angina (severe pain in the chest)
  • Hemoptysis (coughing up blood)
  • Infection (for example lower or upper respiratory tract)
  • Ventilatory impairment or any other lung disease
  • Pneumothorax (gas or air chest cavity)
  • Spirometry
  • Surgery (for example, of the eyes, chest, or stomach); recent may worsen the condition
  • Heart attack
  • Stroke
  • Hypertension
  • Kidney disease

Do not use mannitol if you are allergic to any of the components contained in the medicine. Mannitol accumulation in the body may lead to complications such as heart failure. In addition, mannitol increases the blood flow in the brain and may pose the risk of bleeding after surgery.

Before mannitol is administered, the healthcare provider should evaluate the patient carefully because heart failure may occur when extracellular fluid rapidly expands.

Studies have not yet been conducted to establish whether or not mannitol is harmful to fetuses. Also, it is unclear if the drug can have a negative impact on the reproductive system. Therefore, mannitol should only be administered to a pregnant woman if it is clear that the therapy will be beneficial.

Do not use the medicine if the container is damaged. Do not swallow the capsules or put them in your mouth, they should only be placed inside the inhaler and administered through inhalation route. Any used inhalers should be properly discarded.


Mannitol should be stored at room temperature, which ranges from 20° to 25°C (68° to 77°F). Since this medicine is administered by a healthcare professional in a setting such as a clinic or hospital, it should not be kept at home.

Any medicine that is left over after treatment should be disposed according to the local laws governing poison control.


Mannitol is a diuretic used for diagnosing asthma; on the other hand, it should not be used by patients who are younger than six years of age. The drug is often distributed as a capsule, but it is given through the inhalation route by a healthcare professional.

Although this drug is effective in alleviating these conditions, it still causes several side effects such as chest discomfort, wheezing, runny nose, gagging, migraines, dry mouth, and dehydration. These side effects are usually mild and are often a reaction of the body adjusting to the treatment. However, you should seek medical attention immediately in case the symptoms become severe or chronic.

Drug interactions, pregnancy safety, and dosing should be reviewed before this medication is administered. Talk to your doctor if you have any allergies, including to foods, dyes, animals, prescription medication, or any of the components contained in mannitol.