Aridol (Mannitol)

Bronchial challenge agent for diagnosing airway hyperresponsiveness

Rx – Prescription Only Osmotic Bronchial Challenge Agent
Active Ingredient
Mannitol
Dosage Forms
Inhalation powder (hard capsule), Infusion solution
Strengths
0 mg, 5 mg, 10 mg, 20 mg, 40 mg capsules; 150 mg/ml solution
Known Brands
Aridol, Mannitol Baxter Viaflo, Mannitol Fresenius Kabi
Medically reviewed by iMedic Medical Board
Evidence Level 1A

Aridol is a prescription diagnostic medicine containing mannitol in inhaled powder form. It is used exclusively as a bronchial challenge test to detect airway hyperresponsiveness (BHR), a hallmark of asthma and related conditions. The test is performed under medical supervision in a clinical setting and involves inhaling increasing doses of mannitol while lung function is measured by spirometry. Aridol is not a treatment — it is a diagnostic tool that helps physicians confirm or rule out an asthma diagnosis.

Quick Facts

Active Ingredient
Mannitol
Drug Class
Osmotic Agent
Primary Use
Bronchial Challenge Test
Available Forms
Inhalation Capsule
Prescription Status
Rx Only
Test Duration
20–35 min

Key Takeaways

  • Aridol is a diagnostic test, not a treatment — it is used to detect airway hyperresponsiveness, a key feature of asthma.
  • The test involves inhaling increasing doses of mannitol and measuring lung function with spirometry after each dose.
  • A positive test (15% or greater fall in FEV1) indicates active airway inflammation and hyperresponsiveness.
  • Aridol must only be administered in a clinical setting under the supervision of an experienced physician trained in bronchial challenge testing.
  • The test is not recommended for children under 18 due to limited clinical data, and is contraindicated in pregnancy and patients with recent cardiovascular events.

What Is Aridol and What Is It Used For?

Quick Answer: Aridol is a diagnostic medicine containing inhaled mannitol that is used to test for airway hyperresponsiveness. It helps doctors determine whether a patient's airways are overly sensitive, which is a hallmark feature of asthma. The test is performed in a medical setting and is not a treatment.

Aridol contains the active substance mannitol, a naturally occurring sugar alcohol that acts as an osmotic agent when inhaled into the lungs. It is specifically designed for use in the bronchial provocation test (also known as a bronchial challenge test), which is one of the key diagnostic tools available to physicians investigating suspected asthma and related respiratory conditions.

Airway hyperresponsiveness (BHR) is a condition in which the airways become abnormally sensitive and react excessively to various stimuli. This hypersensitivity is typically caused by underlying inflammation of the airway lining, which makes the smooth muscle surrounding the bronchi more prone to constriction. People with airway hyperresponsiveness often experience difficulty breathing in response to environmental triggers such as exercise, cold air, dust, smoke, and other irritants.

When a person with hyperresponsive airways inhales Aridol, the mannitol creates an osmotic gradient on the airway surface. This draws water out of the airway epithelial cells, which in turn triggers the release of inflammatory mediators such as histamine and prostaglandins from mast cells and other immune cells. These mediators cause the airway smooth muscle to contract, narrowing the airways — a process called bronchoconstriction. This narrowing can be precisely measured using spirometry, which detects changes in the volume of air a person can forcefully exhale in one second (FEV1).

In people who do not have airway hyperresponsiveness, inhaling Aridol will not cause significant airway narrowing. Their airways remain open, and they continue to breathe normally throughout the test. This differential response is what makes the Aridol test a valuable diagnostic tool — it can objectively distinguish between hyperresponsive and normal airways.

Unlike direct bronchial challenge agents such as methacholine, which act directly on smooth muscle receptors, Aridol is classified as an indirect challenge agent. This means it triggers bronchoconstriction through an intermediary pathway involving inflammatory cells. This is clinically significant because indirect agents better mimic the bronchoconstriction caused by real-world triggers such as exercise, and a positive response to an indirect agent is a stronger indicator of active airway inflammation that is likely to respond to anti-inflammatory treatment.

Clinical Significance

A positive Aridol test result indicates that active airway inflammation is present and that the patient is likely to benefit from anti-inflammatory therapy such as inhaled corticosteroids. This makes the test valuable not only for diagnosis but also for guiding treatment decisions and monitoring treatment response over time.

What Should You Know Before Taking Aridol?

Quick Answer: Before the Aridol test, your doctor will check your baseline lung function and review your medical history. The test is contraindicated in patients with severely reduced lung capacity, recent heart attack or stroke, uncontrolled hypertension, or known aortic or cerebral aneurysm. You should avoid caffeine, strenuous exercise, and smoking before the test, and you may need to stop certain medications.

The Aridol bronchial challenge test is a safe and well-established diagnostic procedure when performed in the appropriate clinical setting by trained healthcare professionals. However, like all medical tests, there are important contraindications, precautions, and preparations that must be observed to ensure patient safety and accurate results.

Contraindications

There are several situations in which the Aridol test must not be performed. Your physician will assess these before proceeding with the test:

  • Allergy to mannitol: If you have a known allergy or hypersensitivity to mannitol, you must not undergo the test.
  • Severely reduced lung capacity: Your baseline lung function will be measured before the test. If your forced expiratory volume in one second (FEV1) is significantly below predicted values, the test will not be conducted due to safety concerns.
  • Aortic or cerebral aneurysm: A history of, or current presence of, swelling or weakening of a blood vessel around the heart or brain (aneurysm) is an absolute contraindication.
  • Uncontrolled hypertension: High blood pressure that is not adequately controlled with medication precludes the test.
  • Recent myocardial infarction: If you have had a heart attack within the past 6 months, the test should not be performed.
  • Recent stroke: A cerebrovascular accident (stroke) within the past 6 months is also a contraindication.

Warnings and Precautions

Even if none of the absolute contraindications apply, there are additional situations where extra caution is required. Inform your doctor or healthcare professional before the test if any of the following apply to you:

  • Your lung capacity is moderately reduced (your baseline spirometry will be measured to determine this)
  • You have previously experienced breathing difficulties, wheezing, or coughing during spirometry tests
  • You have been coughing up blood (hemoptysis)
  • You have air in the pleural space (pneumothorax) causing chest pain and shortness of breath
  • You have recently undergone surgery on the abdomen, chest, or eyes
  • You suffer from chest pain (angina pectoris)
  • You have difficulty performing spirometry tests reliably
  • You have had a respiratory tract infection within the past two weeks

During the test, if you experience significant breathlessness, wheezing, or coughing, the healthcare professional will administer a bronchodilator medication (such as salbutamol) to open your airways, and the test will be discontinued. This is a standard safety measure, and all testing facilities are equipped with bronchodilator medications and emergency equipment.

Important Safety Information

Do not take Aridol on your own. The test must only be performed in a suitable laboratory or clinical environment under the direct supervision of an experienced physician. The staff must be thoroughly familiar with bronchial challenge testing procedures and their potential effects, and emergency medication and equipment must be readily available.

Pregnancy and Breastfeeding

Aridol should not be used during pregnancy. If you are pregnant, suspect you may be pregnant, or are planning to become pregnant, inform your doctor before the test. The safety of inhaled mannitol in pregnant women has not been established, and the potential risks to the fetus have not been adequately studied.

Aridol can be used during breastfeeding. Mannitol is a naturally occurring substance with minimal systemic absorption when inhaled, and it is not expected to pass into breast milk in clinically significant amounts. However, you should still inform your doctor if you are breastfeeding before undergoing the test.

Children and Adolescents

Children under 6 years of age should not be given Aridol or undergo the bronchial challenge test. Young children are generally unable to perform the spirometry maneuvers required for the test with sufficient reliability and reproducibility.

Aridol is not recommended for patients aged 6 to 18 years due to limited clinical data on the use of the product in this age group. While the mannitol challenge test has been studied in pediatric populations in research settings, the regulatory evidence base for routine clinical use in children and adolescents remains insufficient. If bronchial challenge testing is needed in pediatric patients, the treating physician will consider alternative diagnostic approaches.

Pre-Test Preparations

To ensure accurate and reliable test results, several preparations are required before the Aridol test:

  • Medications: Certain medications used to treat asthma and allergies can affect how your body responds to the mannitol challenge. Your doctor will instruct you to stop specific medications before the test. The withholding period varies from 6 hours to 4 days depending on the medication class.
  • Caffeine: Avoid coffee, tea, cola, chocolate, and other caffeine-containing foods and beverages on the day of the test, as caffeine has mild bronchodilator properties that could affect results.
  • Exercise: Avoid strenuous physical exercise on the day of the test, especially before the test, as exercise can independently affect airway responsiveness.
  • Smoking: You should refrain from smoking for at least 6 hours before the test, as smoking can alter airway responsiveness and affect the accuracy of spirometry measurements.
Medication Withholding Guide

Short-acting bronchodilators (e.g., salbutamol): withhold for at least 6 hours. Long-acting bronchodilators (e.g., salmeterol, formoterol): withhold for at least 24–48 hours. Antihistamines: withhold for at least 72 hours. Leukotriene receptor antagonists (e.g., montelukast): withhold for at least 4 days. Your physician will provide specific instructions tailored to your medications.

How Does Aridol Interact with Other Drugs?

Quick Answer: Aridol’s primary interactions are with medications that can mask or alter the bronchial challenge test result. Bronchodilators, antihistamines, inhaled corticosteroids, and leukotriene modifiers must be withheld for specified periods before testing. Aridol does not have systemic drug-drug interactions in the traditional sense because it acts locally in the airways and has minimal systemic absorption.

Because Aridol is a diagnostic agent administered as a single test (rather than a continuous therapy), its interaction profile differs significantly from that of most medications. The primary concern is not pharmacokinetic drug-drug interactions, but rather the effect of concurrent medications on the accuracy of the test results. Medications that relax the airway smooth muscle or suppress airway inflammation can produce false-negative results, while medications that increase airway reactivity could theoretically produce false-positive results.

It is essential that you inform your doctor about all medications you are currently taking, have recently taken, or might be taking, so that appropriate withholding periods can be determined.

Medications That Affect Test Results

Medication Withholding Periods Before Aridol Test
Drug Class Examples Withholding Period Effect on Test
Short-acting beta-2 agonists (SABA) Salbutamol, terbutaline 6–8 hours May cause false-negative result by relaxing airway smooth muscle
Long-acting beta-2 agonists (LABA) Salmeterol, formoterol 24–48 hours Prolonged bronchodilation may mask hyperresponsiveness
Ultra-long-acting beta-2 agonists Indacaterol, vilanterol 48 hours Extended bronchodilation may suppress bronchoconstriction
Short-acting anticholinergics Ipratropium 12 hours Bronchodilator effect may reduce airway response
Long-acting anticholinergics Tiotropium, glycopyrronium 72 hours Prolonged anticholinergic effect may reduce reactivity
Antihistamines Cetirizine, loratadine, fexofenadine 72 hours Histamine receptor blockade may reduce mast cell-mediated response
Leukotriene receptor antagonists Montelukast, zafirlukast 4 days Blocks inflammatory mediators involved in bronchoconstriction
Cromones Sodium cromoglycate, nedocromil 24 hours Mast cell stabilization may attenuate response

Inhaled Corticosteroids

Inhaled corticosteroids (ICS) such as budesonide, fluticasone, and beclomethasone suppress airway inflammation over time and can therefore reduce airway hyperresponsiveness. While ICS are not typically required to be withheld for a single test (as their effect is cumulative rather than acute), your physician may ask about your current ICS use when interpreting the test results. A negative Aridol test in a patient currently using ICS may indicate that the anti-inflammatory treatment is effectively controlling airway inflammation, rather than meaning the patient does not have asthma.

The Aridol test can be particularly useful for monitoring treatment response: a shift from a positive to a negative test result after starting ICS therapy indicates that airway inflammation is being adequately controlled. This makes the test a valuable tool for guiding treatment adjustments.

Food, Drink, and Lifestyle Interactions

Caffeine, found in coffee, tea, cola, energy drinks, and chocolate, has mild bronchodilator properties and can affect the test. Avoid all caffeine-containing products on the day of the test. Additionally, strenuous exercise should be avoided on the test day, particularly before the test, as exercise-induced changes in airway caliber can persist for hours and confound the results. Smoking should be avoided for at least 6 hours before the test.

What Is the Correct Dosage of Aridol?

Quick Answer: Aridol is administered as a series of inhaled doses starting from 0 mg (empty capsule) and increasing through 5 mg, 10 mg, 20 mg, and then multiple 40 mg capsules, up to a maximum cumulative dose of 635 mg. Each dose is followed by spirometry to assess lung function. The test ends when a 15% fall in FEV1 is detected or the maximum dose is reached.

The Aridol bronchial challenge test follows a standardized, stepwise dosing protocol. The test is performed entirely by healthcare professionals — you will be guided through each step and will not need to handle the medication on your own. The capsules are loaded into a special inhaler device and are intended for inhalation only. Do not place the capsules in your mouth or swallow them.

Adults

The complete Aridol test kit contains capsules at five different dose levels: 0 mg (empty), 5 mg, 10 mg, 20 mg, and 40 mg. The test follows a structured protocol with progressively increasing cumulative doses:

Aridol Bronchial Challenge Test – Dosing Protocol
Step Dose per Capsule Number of Capsules Cumulative Dose
1 0 mg (empty) 1 0 mg
2 5 mg 1 5 mg
3 10 mg 1 15 mg
4 20 mg 1 35 mg
5 40 mg 1 75 mg
6 40 mg 2 155 mg
7 40 mg 4 315 mg
8 40 mg 4 475 mg
9 40 mg 4 635 mg

Step-by-Step Test Procedure

The Aridol test follows a carefully standardized protocol to ensure safety and accuracy:

  1. Sit comfortably: You will be seated in a comfortable chair throughout the test.
  2. Baseline spirometry: You will be asked to exhale forcefully into a spirometer tube. This establishes your baseline lung function measurement (FEV1).
  3. Nose clip placement: A nose clip is placed on your nose to ensure you breathe only through your mouth during inhalation.
  4. Exhale fully: After breathing out completely, you will inhale the Aridol dose deeply through the special inhaler device.
  5. Breath hold: Hold your breath for 5 seconds after inhalation, then exhale normally.
  6. Nose clip removal: The nose clip is removed and you breathe normally for 60 seconds.
  7. Post-dose spirometry: You perform spirometry again to measure the effect of the dose on your airways.
  8. Repeat: Steps 3–7 are repeated with increasing doses until either a 15% fall in FEV1 is detected (positive test) or the maximum cumulative dose of 635 mg is reached without a significant fall (negative test).
  9. Post-test treatment: At the end of the test, you may receive a bronchodilator medication to help restore your normal lung function.

Children

Children under 6 years of age should not undergo the Aridol bronchial challenge test. For patients aged 6 to 18 years, Aridol is not recommended due to limited clinical evidence in this age group. If a bronchial challenge test is clinically necessary in a pediatric patient, the physician will consider alternative approaches or refer to a specialized pediatric respiratory center.

Elderly

There are no specific dose adjustments required for elderly patients. However, elderly individuals are more likely to have comorbid cardiovascular conditions that could represent contraindications to the test. A thorough medical history and cardiovascular assessment should be performed before the test. Baseline lung function should also be carefully assessed, as age-related changes in lung function may need to be considered when interpreting results.

Overdose

If you believe you may have inhaled too much Aridol, inform the physician or healthcare professional conducting the test immediately. Symptoms of excessive exposure may include breathing difficulties, wheezing, chest tightness, and persistent cough. In the event of significant bronchoconstriction, the medical team will administer a short-acting bronchodilator (such as salbutamol via nebulizer) and supplemental oxygen if needed. Because the test is performed under direct medical supervision, overdose situations are exceptionally rare and can be promptly managed.

What Are the Side Effects of Aridol?

Quick Answer: Common side effects of Aridol include cough, shortness of breath, chest tightness, headache, nausea, and sore throat. These are typically mild and temporary, resolving shortly after the test. If significant bronchoconstriction occurs, a bronchodilator is administered to reverse the effect.

Like all medicines, Aridol can cause side effects, although not everyone experiences them. Because Aridol is designed to provoke a controlled airway response as part of a diagnostic test, some of the “side effects” are actually the expected pharmacological effect of the medication — particularly cough, chest tightness, and breathlessness in patients with hyperresponsive airways. All side effects are typically temporary and resolve within minutes to hours after the test, especially after administration of a bronchodilator.

The following side effects have been reported in clinical studies and post-marketing surveillance:

Common

May affect up to 1 in 10 people
  • Cough (the most frequently reported side effect)
  • Shortness of breath (dyspnea)
  • Chest tightness
  • Asthma exacerbation
  • Headache
  • Nausea
  • Vomiting
  • Sore throat (pharyngolaryngeal pain) and discomfort when swallowing
  • Runny nose (rhinorrhea)

Uncommon

May affect up to 1 in 100 people
  • Cold hands and feet (peripheral circulatory effects)
  • Diarrhea
  • Dizziness
  • Tremor (shakiness)
  • Thirst
  • Fatigue
  • Flushing and sweating
  • Hoarseness
  • Itching and skin rash
  • Itchy eyes
  • Reduced oxygen saturation
  • Mouth ulcers
  • Nosebleed (epistaxis)
  • Stomach pain
  • Muscle and joint soreness

If you experience any side effects during or after the test, inform the healthcare professional immediately. The clinical setting in which the test is performed is equipped to manage all potential adverse reactions. Most side effects resolve spontaneously or after administration of a bronchodilator.

Reporting Side Effects

If you experience side effects from the Aridol test, you can report them through your national pharmacovigilance system. In the European Union, suspected adverse reactions can be reported through the national reporting systems listed on the European Medicines Agency (EMA) website. In the United States, reports can be submitted to the FDA MedWatch program. Reporting side effects helps improve the safety information available about medicines.

How Should You Store Aridol?

Quick Answer: Store Aridol at or below 25°C (77°F) in a dry place. Keep out of reach of children. Do not use after the expiration date. As Aridol is administered in a clinical setting, storage is typically managed by the healthcare facility.

Proper storage of Aridol is essential to maintain the integrity and efficacy of the mannitol inhalation powder. Because Aridol is a diagnostic test administered exclusively in clinical settings, storage is primarily the responsibility of the healthcare facility. However, understanding the storage requirements can help ensure confidence in the quality of the test you receive.

  • Temperature: Store at or below 25°C (77°F). Do not expose to excessive heat or direct sunlight.
  • Moisture protection: Mannitol is hygroscopic, meaning it absorbs moisture from the air. Keep the capsules in their original sealed blister packaging until immediately before use. Do not remove capsules from the blister pack in advance.
  • Keep out of reach of children: Store the product in a location inaccessible to children.
  • Expiration date: Do not use Aridol after the expiration date (EXP) printed on the carton. The expiration date refers to the last day of the indicated month.
  • Disposal: Do not dispose of medicines via wastewater or household waste. Return unused or expired test kits to the pharmacy or healthcare facility for appropriate disposal.

What Does Aridol Contain?

Quick Answer: Each Aridol capsule contains mannitol as its sole active ingredient, available in five dose levels: 0 mg, 5 mg, 10 mg, 20 mg, and 40 mg. The capsules are designed for inhalation only and must not be swallowed. Each test kit includes 19 capsules and one single-use inhaler device.

Aridol is a single-ingredient pharmaceutical product with a straightforward formulation designed for pulmonary delivery:

Active Ingredient

The active substance is mannitol (D-mannitol), a naturally occurring sugar alcohol. Mannitol is widely used in pharmaceutical manufacturing as an excipient and is also used therapeutically as an osmotic diuretic in intravenous formulations. In Aridol, it functions as the active diagnostic agent through its osmotic properties when inhaled.

Capsule Identification

The Aridol test kit capsules are color-coded for easy identification during the test procedure:

Aridol Capsule Identification Guide
Dose Capsule Appearance Marking
0 mg (empty) Completely clear with two white bands None
5 mg Half white, half clear 5 mg
10 mg Half yellow, half clear 10 mg
20 mg Half pink, half clear 20 mg
40 mg Half red, half clear 40 mg

Package Contents

Each Aridol diagnostic test kit is packaged in a carton and contains the following:

  • 1 empty capsule (0 mg) — clear with white bands
  • 1 capsule of 5 mg mannitol
  • 1 capsule of 10 mg mannitol
  • 1 capsule of 20 mg mannitol
  • 15 capsules of 40 mg mannitol
  • 1 single-use inhaler device

The capsules are sealed in blister packs to protect them from moisture and physical damage. The powder inside the capsules is white or almost white in appearance.

Manufacturer Information

The marketing authorization holder for Aridol is Pharmaxis Europe Limited, based in Dublin, Ireland. The product is manufactured by MIAS Pharma Limited, also based in Dublin, Ireland. Aridol is approved for use in the European Union and several other countries worldwide as a diagnostic agent for bronchial challenge testing.

Mannitol is also available under other brand names for different indications, including Mannitol Baxter Viaflo and Mannitol Fresenius Kabi (150 mg/ml infusion solutions), which are used intravenously as osmotic diuretics — an entirely different therapeutic application from the inhaled Aridol product.

Frequently Asked Questions About Aridol

Medical References and Sources

This article is based on current medical research and international guidelines. All claims are supported by scientific evidence from peer-reviewed sources.

  1. Anderson SD, et al. (2009). “Provocation by eucapnic voluntary hyperpnoea to identify exercise induced bronchoconstriction.” British Journal of Sports Medicine. 43(9):683–689. Landmark study on indirect bronchial challenge methods including mannitol.
  2. Brannan JD, et al. (2005). “Inhaled mannitol identifies a subgroup of exercise-induced asthma not identified by exercise testing.” Respirology. 10(Suppl):A149. Clinical evidence for mannitol challenge specificity in exercise-induced asthma.
  3. European Medicines Agency (EMA). “Aridol – Summary of Product Characteristics (SmPC).” EMA Product Information Official European regulatory product information for Aridol.
  4. Coates AL, et al. (2017). “ERS Technical Standard on Bronchial Challenge Testing: General Considerations and Performance of Methacholine Challenge Tests.” European Respiratory Journal. 49(5):1601526. https://doi.org/10.1183/13993003.01526-2016 ERS/ATS technical standards for bronchial challenge testing procedures. Evidence level: 1A
  5. Anderson SD, Brannan JD. (2003). “Methods for ‘indirect’ challenge tests including exercise, eucapnic voluntary hyperpnea, and hypertonic aerosols.” Clinical Reviews in Allergy & Immunology. 24(1):27–54. Comprehensive review of indirect bronchial challenge testing including mannitol.
  6. Global Initiative for Asthma (GINA) (2024). “Global Strategy for Asthma Management and Prevention.” GINA Report International guidelines for asthma diagnosis and management, including bronchial challenge testing.
  7. World Health Organization (WHO). “Model List of Essential Medicines.” WHO Essential Medicines List WHO reference for essential medicines including mannitol.

Evidence grading: This article uses the GRADE framework (Grading of Recommendations Assessment, Development and Evaluation) for evidence-based medicine. Evidence level 1A represents the highest quality of evidence, based on systematic reviews of randomized controlled trials.

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iMedic Medical Editorial Team

Specialists in pulmonology, clinical pharmacology and respiratory medicine

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