What is aerosol therapy?
Aerosol therapy is a technique of administering medication directly into the airway and lungs. An aerosol is a suspension of liquid and/or solid particles, usually administered by a medical device like an inhaler. A medical device is used to convert the medication into fine aerosol particles which can be inhaled or propelled directly into the airway and lungs. Bronchodilators and corticosteroids are the most commonly administered inhalation medications.
What are the uses of aerosol therapy?
The primary use of aerosol therapy is treatment of respiratory disorders that include:
- Obstructive lung diseases such as:
- Pulmonary arterial hypertension
- Infectious pulmonary diseases
With the advent of macromolecular (molecules of high mass) medications, aerosol therapy is being investigated for use in many non-respiratory systemic diseases. Inhalation therapy can be a convenient alternative to injections for chronic conditions, and improve patient comfort.
Macromolecular medications, because of their biochemical properties, are unsuitable for oral intake and require parenteral administration (injections into skin, muscle or veins). Advancement in aerosol delivery systems has enabled better efficiency and accuracy in delivering medications directly to the lungs, where they are rapidly absorbed into the bloodstream.
Aerosol therapy is currently being studied for use in several non-respiratory conditions that include:
What are the benefits of an aerosol treatment?
The benefits of aerosol treatment include the following:
- Direct delivery to the treatment site
- Faster onset of action than oral medication
- Lower requirement of dosage than systemic administration
- Reduced systemic adverse effects
What are the modes of aerosol drug delivery?
Following are the modes of aerosol drug delivery:
Metered dose inhalers
A metered dose inhaler (MDI) is a handheld device that uses a pressurized metal canister with a metering valve to deliver precise doses of medication. The canister is encased in a plastic sleeve with a mouthpiece to use for inhalation. The canister is pressed down (actuation) to release a measured dose of medication.
The canister contains a combination of the following:
- The medication as a solution or suspension.
- A surfactant, which is a substance that reduces surface tension and helps disperse the solution into aerosol particles.
- A propellant that propels the particles forward.
- Can deliver multiple doses
- Low risk of bacterial contamination
- Need for actuation and inhalation to be precisely coordinated
- Deposition of the medication in the mouth and throat
- Possible flammability of the pressurized propellant
- Cannot be used by people with sensitivity or cardiotoxicity to propellants
Inhalation accessory devices
Inhalation accessory devices enhance the action of metered dose inhalers. These devices are attached to the mouthpiece of the metered dose inhalers to expand and slow down the propelled high-pressure spray into a fine mist. There are two types of inhalation accessory devices:
- Spacers: Spacers are devices that provide space for the aerosol spray to slow down and become a fine mist. Children can use spacers with a pediatric mask. There are two types of spacers:
- Open tube spacers: An open tube spacer is an extension that provides extra space to slow down the spray.
- Reverse-flow spacers: Reverse-flow spacers direct the flow of drug away from the spacer’s mouthpiece and sound an alert if the patient inhales too quickly.
- Valved holding chambers: Valved holding chambers have a one-way valve which keeps the mist of medication inside the spacer until the patient inhales through the valve. Most devices sound an alert if the patient inhales too quickly.
- Enhanced drug delivery
- Removes the need for coordination of inhalation with actuation
- Prevents exhalation of air into the device
- Reduced drug deposition in the mouth and throat
- Bulkier in size and volume
- Possible bacterial contamination; must be regularly cleaned
- Static electricity may reduce drug delivery to the lungs
Dry powder inhalers
Dry powder inhalers (DPI) are devices that contain medication in the form of minute particles inside a capsule or blister. The blister/capsule is punctured before inhaling the medication through the mouthpiece. Dry powder inhalers do not use any propellant and are actuated by the patient’s breathing.
Following are some of the types of dry powder inhalers:
- Diskus: A disk shaped device with a coiled strip of blisters punctured with a rotating wheel.
- Aerolizer: A plastic device with a button to puncture capsules.
- HandiHaler: A spherical plastic device with a button to puncture capsules.
- Twisthaler: A device with a twisting mechanism to deliver measured doses of dry powder medication.
- Flexhaler: A device that uses a twisting motion to puncture capsules.
- No propellant
- No need of spacers
- Actuated by breath, so no need of coordination
- Require good inhalation flow rate, so are not appropriate for patients with acute asthma attacks or children with reduced lung function
- Drug deposition in the throat
- Humidity may cause the powder to clump and prevent dispersal
Nebulizers are electrical devices that transform drug solutions into breathable aerosol particles, in a process known as nebulization. Tabletop nebulizers can be plugged into wall sockets, while portable models run on batteries.
Nebulizers are useful for administering inhalation medication to patients who are too ill or too young to use other inhaling devices. Nebulizers can be used with a mouthpiece or a mask.
There are three types of nebulizers:
- Pneumatic jet nebulizer: Uses compressed gas to nebulize the solution. A powered compressor sends pressurized air or oxygen through a tubing into a cup of liquid medication aerosolizing it.
- Ultrasonic nebulizer: A compact single unit that uses high-frequency vibrations to nebulize the medication. The aerosol particles may be slightly larger than those produced by jet nebulizers. Ultrasonic nebulizers are not efficient in nebulizing suspensions.
- Mesh nebulizer: Mesh nebulizers are portable battery-operated devices that use a very fine mesh to break up the solution into aerosol particles. Mesh nebulizers are the latest products and produce the finest aerosol particles, but are also the most expensive.
- Useful for patients who cannot use other types of inhalation devices
- Large doses of medicine can be administered
- Patient coordination is not required
- Higher cost
- Harder to carry around
- Takes longer to set up and administer medication
- Jet nebulizers need a compressed gas source.
Latest Lungs News
Daily Health News
Aerosol therapy is a technique of administering medication directly into the airway and lungs. An aerosol is a suspension of liquid and/or solid particles, usually administered by a medical device like an inhaler. A medical device is used to convert the medication into fine aerosol particles which can be inhaled or propelled directly into the airway and lungs.
Multimedia: Slideshows, Images & Quizzes
Asthma Quiz: Test Your Medical IQ
Asthma is a chronic disease of the airways of the lungs, which can be managed with proper treatment. Triggered by two main...
What is Asthma? Asthma Myths Debunked
There is currently no cure for asthma, and no specific, single cause for asthma has been identified. Take this quiz on asthma...
What Is Asthma? Symptoms, Causes, and Treatments
What is asthma? Learn information about asthma, a chronic disease of the bronchiole tubes. Discover information about asthma...
Worst Smog Cities in Pictures: Air Pollution, Ozone, and Asthma
Learn the worst smog cities in America. See the 10 cities with the most polluted, unclean and smoggy air.
Asthma Attacks: Triggers, Symptoms, and Treatment
Asthma symptoms include coughing, wheezing, headache, fatigue, dark circles under the eyes, trouble sleeping, and loss of...
Asthma: Natural Ways to Ease Asthma Symptoms
You can do more than take medication to manage your asthma. Several other things can help you breathe more easily.
Related Disease Conditions
Asthma is a condition in which hyperreactive airways constrict and result in symptoms like wheezing, coughing, and shortness of breath. Causes of asthma include genetics, environmental factors, personal history of allergies, and other factors. Asthma is diagnosed by a physician based on a patient's family history and results from lung function tests and other exams. Inhaled corticosteroids (ICS) and long-acting bronchodilators (LABAs) are used in the treatment of asthma. Generally, the prognosis for a patient with asthma is good. Exposure to allergens found on farms may protect against asthma symptoms.
Asthma: Over the Counter Treatment
Patients who have infrequent, mild bouts of asthma attacks may use over-the-counter (OTC) medications to treat their asthma symptoms. OTC asthma medicines are limited to epinephrine and ephedrine. These OTC drugs are best used with the guidance of a physician, as there may be side effects and the drugs may not be very effective.
There are many unusual symptoms of asthma, including sighing, difficulty sleeping, anxiety, chronic cough, recurrent walking pneumonia, and rapid breathing. These symptoms may vary from individual to individual. These asthma complexities make it difficult to accurately diagnose and treat asthma.
Asthma in Children
Asthma in children manifests with symptoms such as coughing and wheezing. Rates of asthma in children are increasing. Asthma in children is usually diagnosed based on the description of symptoms. Lung function tests may also be used. A variety of medications are used for the treatment of childhood asthma.
Adult-onset asthma is asthma that is diagnosed in people over 20 years of age. Symptoms include wheezing, coughing, shortness of breath and difficulty breathing. Treatment may involve anti-inflammatory medications or bronchodilators.
Exercise-induced asthma is asthma triggered by vigorous exercise. Symptoms include coughing, shortness of breath, chest tightness, wheezing, and fatigue while exercising. Preventing exercise-induced asthma attacks involves using inhaled medicines before exercising, performing warm-up exercises and cooling down afterward, avoiding exercising outdoors when pollen counts are high, restricting exercise when you have a viral infection, and wearing a mask over your nose and mouth when exercising in cold weather.
There are two types of asthma medications: long-term control with anti-inflammatory drugs and quick relief from bronchodilators. Asthma medicines may be inhaled using a metered-dose inhaler or nebulizer or they may be taken orally. People with high blood pressure, diabetes, thyroid disease, or heart disease shouldn't take OTC asthma drugs like Primatene Mist and Bronkaid.
Occupational asthma is a type of asthma caused by exposure to a substance in the workplace. Symptoms and signs include wheezing, chest tightness, and shortness of breath. The usual treatment for occupational asthma involves removal from exposure and the use of bronchodilators and inhaled anti-inflammatory medicines.
COPD vs. Asthma (Differences and Similarities)
COPD (chronic obstructive pulmonary disease) and asthma both have common symptoms like coughing, wheezing, shortness of breath, and a tight feeling in the chest. COPD is caused by tobacco smoking, while asthma is caused by your inherited genetic makeup and their interactions with the environment. Risk factors for asthma are obesity, exposure to cigarette smoke (even secondhand smoke), and personal history of hay fever. There is no cure for either disease, but symptoms can be managed with medication. A person with asthma has a better prognosis and life expectancy than someone with COPD.
What Are the Four Types of Asthma?
Asthma is a chronic inflammatory disease of the airways (bronchi). Bronchi generally allow for the passage of air in and out of the lungs. In asthma, these airways develop hypersensitivity, inflammation, and narrowing. This causes difficulty in breathing. The four types are mild intermittent, mild persistent, moderate persistent and severe persistent.
Can asthma go away?
Asthma is a long-term condition for many people, particularly if it first develops when you're an adult. In children, it sometimes goes away or improves during the teenage years, but can come back later in life.
Treatment & Diagnosis
- Asthma FAQs
- What if I Get COVID-19 with Asthma?
- Methotrexate Spares Steroids in Asthmatics
- Asthma Rates Increasing
- Exercise Preventing Asthma?
- Asthma in Women, Asthma in Pregnancy
- What Is Exercise-Induced Asthma?
- Can Asthma Medication Hide Churg-Strauss Syndrome?
- Can Asthma Go Away and Come Back?
- What Are the Side Effects of Asthma Inhalers?
- Does Altitude Affect Asthma?
- Best Exercises for Asthma: Yoga, Swimming, Biking, and Walking
- Does Stress Cause Asthma?
- Can Asthma Cause a Heart Attack?
- What Causes Asthma?
Medications & Supplements
- cromolyn aerosol - inhalation, Intal
- albuterol (Ventolin, Proventil)
- ipratropium bromide inhaler (Atrovent)
- fluticasone (Flonase, Flonase Allergy Relief)
- Advair Diskus, Advair HFA (fluticasone and salmeterol oral inhaler)
- fluticasone disk inhaler - oral, Flovent Rotadisk
- Dymista (azelastine hydrochloride and fluticasone propionate)
- Breo vs Albuterol
- Advair Diskus (fluticasone propionate and salmeterol inhaler) Side Effects, Warnings & Interactions
- ArmonAir Digihaler (fluticasone propionate inhalation powder)
Prevention & Wellness
- Asthma from Cockroach Allergy?
- Asthma Specific References
- Allergies-Asthma Organizations
- Asthma: Everyday Pain Relief
- Asthma and Pain Relievers
- Asthma: Do You Have Asthma?
- Managing Asthma
- Asthma: Early Warning Signs of Asthma
- Asthma: Helping City Kids With Asthma
- Asthma: Help Teachers, Coaches and Students
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.