Inhaler


An inhaler is a medical device used for delivering medicines into the lungs through the work of a person's breathing. This allows medicines to be delivered to and absorbed in the lungs, which provides the ability for targeted medical treatment to this specific region of the body, as well as a reduction in the side effects of oral medications. There are a wide variety of inhalers, and they are commonly used to treat numerous medical conditions with asthma and chronic obstructive pulmonary disease being among the most notable.
Some of the common types of inhalers include metered-dose inhalers, dry powder inhalers, soft mist inhalers, and nebulizers. Each device has advantages and disadvantages and can be selected based on individually specific patient needs, as well as age, pathological conditions, coordination, and lung function. Proper education on inhaler use is important to ensure that inhaled medication creates its proper effects in the lungs. Using a spacer can ensure that more medicine reaches the lungs, thus providing the most optimal treatment.

Medical uses

Inhalers are designed to deliver medication directly to the lungs through a person's own breathing. This may benefit a patient by providing medicines directly to areas of disease, allowing medication to take a greater effect on its intended target, and limit side effects of medications when administered locally. Inhalers are used in a variety of different medical conditions with diseases of the lungs and respiratory system being among the most common. Individuals with these diseases/conditions need medications designed to decrease airway inflammation and obstruction to allow for easier and comfortable breathing. Antibiotic medications have even been developed for inhalers to allow for direct delivery to areas of infection within the lungs. Two of the most common conditions that warrant inhaler therapy are asthma and chronic obstructive pulmonary disease.

Asthma

is a condition of intermittent airway obstruction due to inflammatory processes in the lungs. Inhaled medications are used to calm down the inflammation present in the lungs and allow for relief of the airway obstruction. Common inhaled medications used for treatment of asthma include long term inhalational steroidal anti-inflammatory drugs and fast-relieving bronchodilators such as salbutamol and salmeterol. These medications allow for patients to have relief of airway obstruction symptoms and reduced inflammation. If some people are unable to use inhalers, non-steroidal anti-inflammatory drugs may be used, but with caution since they may cause immunological hypersensitivity to NSAIDs, resulting in respiratory-related symptoms such as bronchospasms, acute asthma exacerbation, and severe asthma morbidity.

Chronic obstructive pulmonary disease (COPD)

COPD is an obstructive lung disease due to long-term damage to the airways of the lungs. The long-term damage leads to the inability of the airways to open properly, causing airway obstruction. Inhaled medications allow patients to see improvement in symptoms and better function of daily living. Some commonly used inhaled medications in patient's with COPD are ipratroprium, salmeterol, and corticosteroids. Inhalers that combine two or three different medications including inhaled corticosteroids, long-active muscarinic medications and long acting beta2 agonists for treating COPD may be associated with improvements in some quality of life variables and small improvements in lung function and respiratory symptoms, however, may also be associated with an increase in the risk of pneumonia.

Types of inhalers

Meter-dosed inhaler (MDI)

The most common type of inhaler is the pressurized metered-dose inhaler which is made up of 3 standard components- a metal canister, plastic actuator, and a metering valve. The medication is typically stored in solution in a pressurized canister that contains a propellant or suspension. The MDI canister is attached to a plastic, hand-operated actuator. On activation, the metered-dose inhaler releases a fixed dose of medication in aerosol form through the actuator and into a patient's lungs. These devices require significant coordination as a person must discharge the medication at or near the same time that they inhale in order for the medication to be effective. This problem is mitigated by the use of a spacer chamber, which allows the fine particle suspension to slow down and be more effectively inhaled into the lower airways. It is preferable that a spacer chamber is used for delivering medication by MDI for all age groups.

Dry powder inhaler (DPI)

s release a metered or device-measured dose of powdered medication that is inhaled through a DPI device. This device usually contains a chamber in which the powdered medication is deposited prior to each dosage. The powder can then be inhaled with a quick breath. This allows for medication to be delivered to the lungs without the need for use of propellant/suspension.

Soft mist inhaler (SMI)

Soft mist inhalers release a light mist containing medication without the need for a propellant/suspension. Upon pressing a button, the inhaler creates a mist of medication, allowing for inhalation into the lungs. SMIs suspend inhaled medications for roughly 1.2 seconds, which is longer than the average MDI inhaler suspension time period. This requires less coordination when using and may be helpful for young patients or patients that find the MDI inhalers difficult to use.

Nebulizer

s are designed to deliver medications over an extended period of time over multiple breaths through a mouthpiece or face mask. They generate a continuous mist with aerosolized medication, allowing a patient to breathe normally and receive medications. They are commonly used in infants and toddlers requiring inhaled medications or in patients in the hospital who require inhaled medications.

Smart inhaler

The smart-inhaler is an inhaler that will automatically update an app with information that includes the time of day, air quality, and how many times it has been used through sensor technology on the device. The first smart-inhaler was approved in 2019 by the FDA, its purpose is to track patient use of the device and some other circumstantial factors that could affect the effectiveness of the dosage. This information is sent via Bluetooth to a mobile device app, and is later shared with their physician to determine what kind of things can trigger issues with asthma and other problems. This technology presents a great way to cut down on medical costs associated with asthma and also help patients better manage their condition with fewer emergencies.
The Teva ProAir Digihaler was the first FDA approved smart inhaler. It shows how effective the device is at aiding patients in using the proper dose amount for their asthma. In a study published by the European Respiratory Journal, the ProAir Digihaler accurately identified when patients were using their inhalers and whether they were effectively administering the dose in a 370 patient trial with the device. This study further gives an overview on the technology regarding applications and devices that help aid in the tracking and medication management for asthma and other lung conditions. Another study showed that smart inhalers accurately recorded all doses administered by patients with their technology, which signifies their importance in providing accurate dosage information to patients and their physicians.

Propellants

In 2009, the FDA banned the use of inhalers that use chlorofluorocarbons as propellants. In their place, inhalers now use hydrofluorocarbons, which are also called hydrofluoroalkanes. HFCs are greenhouse gases, but do not deplete the ozone layer. While some people with asthma and advocacy groups contend that HFC inhalers are not as effective, published clinical studies indicate CFC and HFC inhalers are equally effective in controlling asthma.
While the impact of CFCs from inhalers on the ozone layer had been minuscule, the FDA in its interpretation of the Montreal Protocol mandated the switch in propellants. Patients expressed concern about the high price of the HFA inhalers as there were initially no generic versions, whereas generic CFC inhalers had been available.

Proper use

It is important to use proper techniques when administering medications through inhalers.
Proper use of inhalers often involves initial deep breathing, and then rapid breathing during intake of one or more puffs from the inhalers.
Improper use of inhalers is very common, can lead to distribution of the medicine into the mouth or throat where it cannot create its desired effect and may cause harm. Education on the correct use of inhalers for delivery of medications is a commonly cited topic in medical studies and a great deal of thought has been put into how best to help people learn to use their inhalers effectively. Below is a description of proper inhaler technique for each different type of inhaler as well as a helpful video explaining what the text states.

Meter-dosed inhalers

  1. The mouthpiece is removed and the inhaler is shaken for 5–10 seconds.
  2. The inhaler is gripped with mouthpiece on the bottom and canister on top. A finger is placed on the canister to allow for delivery of medicine.
  3. Deep inhalation is done until no more air can be taken into the lungs.
  4. Deep exhalation is done until most of the air is out of the lungs.
  5. Once deep exhalation is done, mouth is placed over mouthpiece.
  6. As the next deep inhalation begins, the canister is pressed down to release the medicine into the lungs.
  7. Slow deep breathing is continued and breath is held for 5–10 seconds, keeping the medicine in the lungs for a longer time period and preventing escape of aerosolized form of the medicine.
  8. Complete exhalation is done again. If multiple puffs of the medicine have to be taken, steps 1–5 are repeated after waiting for 15–30 seconds.
  9. Mouthpiece is replaced.