Inhaler | |
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Specialty | pulmonology |
An inhaler (puffer, asthma pump or allergy spray) 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 (COPD) being among the most notable. [1]
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. [2] Proper education on inhaler use is important to ensure that inhaled medication creates its proper effects in the lungs. [3] Using a spacer can ensure that more medicine reaches the lungs, [4] [5] thus providing the most optimal treatment.
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. [1] 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. [6] Antibiotic medications have even been developed for inhalers to allow for direct delivery to areas of infection within the lungs. [7] Two of the most common conditions that warrant inhaler therapy are asthma and chronic obstructive pulmonary disease. [6] [8]
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 (most commonly inhaled corticosteroids, also called ICS) and fast-relieving bronchodilators such as salbutamol (known commonly as "Ventolin") and salmeterol. These medications allow for patients to have relief of airway obstruction symptoms and reduced inflammation. [6] If some people are unable to use inhalers, non-steroidal anti-inflammatory drugs (NSAIDs) 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. [9] [10]
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. [8] Inhalers that combine two or three different medications including inhaled corticosteroids, long-active muscarinic medications (LAMA) and long acting beta2 agonists (LABA) 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. [11]
The most common type of inhaler is the pressurized metered-dose inhaler (MDI) 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. [12] 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. [13]
Dry powder inhalers 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. [3] The powder can then be inhaled with a quick breath. [1] This allows for medication to be delivered to the lungs without the need for use of propellant/suspension. [13]
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. [13]
Nebulizers 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. [13] They are commonly used in infants and toddlers requiring inhaled medications or in patients in the hospital who require inhaled medications. [2]
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. [14] 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. [14] 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. [14] 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. [15] 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. [15] 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. [16]
In 2009, the FDA banned the use of inhalers that use chlorofluorocarbons (CFC) as propellants. In their place, inhalers now use hydrofluoroalkane (HFA). HFA is not environmentally inert as it is a greenhouse gas but it does not affect the ozone layer. [17] While some people with asthma and advocacy groups contend that HFA inhalers are not as effective, [18] published clinical studies indicate CFC and HFA inhalers are equally effective in controlling asthma. [19]
While the impact of CFCs from inhalers on the ozone layer had been minuscule (dwarfed by industrial processes using CFCs), the FDA in its interpretation of the Montreal Protocol mandated the switch in propellants. [17] 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. [18]
This section is written like a manual or guide.(August 2021) |
It is important to use proper techniques when administering medications through inhalers.
Proper use of inhalers often involves initial deep breathing (which involves mostly the diaphragm's movements), and then rapid breathing [20] (which involves most of the muscles of respiration, such as external and internal intercostal muscles [21] ) 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. [1] [22] [23] 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. [24] [3] 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.
Spacer is placed at the mouthpiece of a meter-dosed inhaler while keeping mouth at the end of the spacer. After pressing the canister of the inhaler, the medicine will linger inside the spacer, allowing for the user of the inhaler to directly absorb medicine into their lungs. [25] Deep breathing is done to be ready for the delivery of the medicine to the lungs; this minimizes need for coordination of breathing with inhaler activation. [1] Cleanage of the spacer regularly with warm soapy water is recommended. [25] [5]
If inhaler is used everyday, the inhaler usually has to be primed the first time using a new cartridge, but it may need to be primed again if it has not been used in multiple days. [1]
If using inhaled corticosteroids, one should wash the mouth out directly after use of an inhaler. This helps to prevent mouth infections that can occur due to immunosuppressant effects of corticosteroids. [1]
In the United States, pharmaceutical manufacturers use legal and regulatory strategies to keep inhaler prices artificially high. There has been little innovation in inhaler technology for decades — the most recent drug to be approved by the FDA for treating asthma or COPD via a novel target of action was Ipratropium bromide in 1986. Since then, manufacturers have used small changes to drug delivery mechanisms, or have switched active ingredients from one inhaler device to another (a strategy known as a "device hop") to keep patents active. This has the effect of limiting competition, keeping inhalers expensive. [26] Because of high prices, patients sometimes skip doses or give up using their inhalers.
The idea of directly delivering medication into the lungs was based on ancient traditional cures that involved the use of aromatic and medicinal vapors. These did not involve any special devices beyond the apparatus used for burning or heating to produce fumes. Early inhalation devices included one devised by John Mudge in 1778. It had a pewter mug with a hole allowing attachment of a flexible tube. Mudge used it for the treatment of coughs using opium. These devices evolved with modifications by Wolfe, Mackenzie (1872) and better mouth attachments such as by Beigel in 1866. Many of these early inhalers needed heat to vaporize the active chemical ingredient. The benefits of forced expiration and inspiration to treat asthma were noted by J. S. Monell in 1865. Chemicals used in inhalers included ammonia, chlorine, iodine, tar, balsams, turpentine camphor and numerous others in combinations. [27] Julius Mount Bleyer used a variation in 1890 in New York. [28]
In 1968, Robert Wexler of Abbott Laboratories developed the Analgizer, a disposable inhaler that allowed the self-administration of methoxyflurane vapor in air for analgesia. [29] The Analgizer consisted of a polyethylene cylinder 5 inches long and 1 inch in diameter with a 1 inch long mouthpiece. The device contained a rolled wick of polypropylene felt which held 15 milliliters of methoxyflurane.
Because of the simplicity of the Analgizer and the pharmacological characteristics of methoxyflurane, it was easy for patients to self-administer the drug and rapidly achieve a level of conscious analgesia which could be maintained and adjusted as necessary over a period of time lasting from a few minutes to several hours. The 15 milliliter supply of methoxyflurane would typically last for two to three hours, during which time the user would often be partly amnesic to the sense of pain; the device could be refilled if necessary. [30]
The Analgizer was found to be safe, effective, and simple to administer in obstetric patients during childbirth, as well as for patients with bone fractures and joint dislocations, [30] and for dressing changes on burn patients. [31] When used for labor analgesia, the Analgizer allows labor to progress normally and with no apparent adverse effect on Apgar scores. [30] All vital signs remain normal in obstetric patients, newborns, and injured patients. [30] The Analgizer was widely utilized for analgesia and sedation until the early 1970s, in a manner that foreshadowed the patient-controlled analgesia infusion pumps of today. [32] [33] [34] [35] The Analgizer inhaler was withdrawn in 1974, but use of methoxyflurane as a sedative and analgesic continues in Australia and New Zealand in the form of the Penthrox inhaler. [36] [37] [38] [39] [40] [41]
A bronchodilator or broncholytic is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be originating naturally within the body, or they may be medications administered for the treatment of breathing difficulties, usually in the form of inhalers. They are most useful in obstructive lung diseases, of which asthma and chronic obstructive pulmonary disease are the most common conditions. Although this remains somewhat controversial, they might be useful in bronchiolitis and bronchiectasis. They are often prescribed but of unproven significance in restrictive lung diseases.
A spacer is a device used to increase the ease of giving aerosolized medication from a metered-dose inhaler (MDI). It adds space in the form of a tube or "chamber" between the mouth and canister of medication. Most spacers have a one-way valve that allows the person to inhale the medication while inhaling and exhaling normally; these are often referred to as valved holding chambers (VHC).
Oxygen therapy, also referred to as supplemental oxygen, is the use of oxygen as medical treatment. Supplemental oxygen can also refer to the use of oxygen enriched air at altitude. Acute indications for therapy include hypoxemia, carbon monoxide toxicity and cluster headache. It may also be prophylactically given to maintain blood oxygen levels during the induction of anesthesia. Oxygen therapy is often useful in chronic hypoxemia caused by conditions such as severe COPD or cystic fibrosis. Oxygen can be delivered via nasal cannula, face mask, or endotracheal intubation at normal atmospheric pressure, or in a hyperbaric chamber. It can also be given through bypassing the airway, such as in ECMO therapy.
In medicine, a nebulizer or nebuliser is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of asthma, cystic fibrosis, COPD and other respiratory diseases or disorders. They use oxygen, compressed air or ultrasonic power to break up solutions and suspensions into small aerosol droplets that are inhaled from the mouthpiece of the device. An aerosol is a mixture of gas and solid or liquid particles.
Ipratropium bromide, sold under the trade name Atrovent among others, is a type of anticholinergic medication which is applied by different routes: inhaler, nebulizer, or nasal spray, for different reasons.
Budesonide/formoterol, sold under the brand name Symbicort among others, is a fixed-dose combination medication used in the management of asthma or chronic obstructive pulmonary disease (COPD). It contains budesonide, a steroid; and formoterol, a long-acting β2-agonist (LABA). The product monograph does not support its use for sudden worsening or treatment of active bronchospasm. However, a 2020 review of the literature does support such use. It is used by breathing in the medication.
Beta2-adrenergic agonists, also known as adrenergic β2 receptor agonists, are a class of drugs that act on the β2 adrenergic receptor. Like other β adrenergic agonists, they cause smooth muscle relaxation. β2 adrenergic agonists' effects on smooth muscle cause dilation of bronchial passages, vasodilation in muscle and liver, relaxation of uterine muscle, and release of insulin. They are primarily used to treat asthma and other pulmonary disorders. Bronchodilators are considered an important treatment regime for chronic obstructive pulmonary disease (COPD) and are usually used in combination with short acting medications and long acting medications in a combined inhaler.
Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath.
A metered-dose inhaler (MDI) is a device that delivers a specific amount of medication to the lungs in the form of a short burst of aerosolized medicine that is usually self-administered by the patient via inhalation. It is the most commonly used delivery system for treating asthma, chronic obstructive pulmonary disease (COPD) and other respiratory diseases. The medication in a metered dose inhaler is most commonly a bronchodilator, corticosteroid or a combination of both for treating asthma and COPD. Other medications less commonly used but also administered by MDI are mast cell stabilizers, such as cromoglicate or nedocromil.
Methoxyflurane, sold under the brand name Penthrox among others, is an inhaled medication primarily used to reduce pain following trauma. It may also be used for short episodes of pain as a result of medical procedures. Onset of pain relief is rapid and of a short duration. Use is only recommended with direct medical supervision.
A dry-powder inhaler (DPI) is a device that delivers medication to the lungs in the form of a dry powder. DPIs are commonly used to treat respiratory diseases such as asthma, bronchitis, emphysema and COPD although DPIs have also been used in the treatment of diabetes mellitus.
Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. Many obstructive diseases of the lung result from narrowing (obstruction) of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, problems exhaling, and frequent medical clinic visits and hospitalizations. Types of obstructive lung disease include asthma, bronchiectasis, bronchitis and chronic obstructive pulmonary disease (COPD). Although COPD shares similar characteristics with all other obstructive lung diseases, such as the signs of coughing and wheezing, they are distinct conditions in terms of disease onset, frequency of symptoms, and reversibility of airway obstruction. Cystic fibrosis is also sometimes included in obstructive pulmonary disease.
Pulmonary function testing (PFT) is a complete evaluation of the respiratory system including patient history, physical examinations, and tests of pulmonary function. The primary purpose of pulmonary function testing is to identify the severity of pulmonary impairment. Pulmonary function testing has diagnostic and therapeutic roles and helps clinicians answer some general questions about patients with lung disease. PFTs are normally performed by a pulmonary function technologist, respiratory therapist, respiratory physiologist, physiotherapist, pulmonologist, or general practitioner.
Tiotropium bromide, sold under the brand name Spiriva among others, is a long-acting bronchodilator used in the management of chronic obstructive pulmonary disease (COPD) and asthma. Specifically it is used during periods of breathing difficulty to prevent them from getting worse, rather than to prevent them from happening. It is used by inhalation through the mouth. Onset typically begins within half an hour and lasts for 24 hours.
Patient-controlled analgesia (PCA) is any method of allowing a person in pain to administer their own pain relief. The infusion is programmable by the prescriber. If it is programmed and functioning as intended, the machine is unlikely to deliver an overdose of medication. Providers must always observe the first administration of any PCA medication which has not already been administered by the provider to respond to allergic reactions.
Pursed-lip breathing (PLB) is a breathing technique that consists of exhaling through tightly pressed (pursed) lips and inhaling through the nose with the mouth closed.
The post bronchodilator test, also commonly referred to as a reversibility test, is a test that utilizes spirometry to assess possible reversibility of bronchoconstriction in diseases such as asthma.
Beclometasone/formoterol/glycopyrronium, sold under the brand name Trimbow among others, is an inhalable fixed-dose combination medication for the treatment of chronic obstructive pulmonary disease (COPD) and asthma. It contains beclometasone dipropionate, formoterol fumarate dihydrate, and glycopyrronium bromide.
Fluticasone furoate/umeclidinium bromide/vilanterol, sold under the brand name Trelegy Ellipta among others, is a fixed-dose combination inhaled medication that is used for the maintenance treatment of chronic obstructive pulmonary disease (COPD). The medications work in different ways: fluticasone furoate is an inhaled corticosteroid (ICS), umeclidinium is a long-acting muscarinic antagonist (LAMA), and vilanterol is a long-acting beta-agonist (LABA).
Pulmonary drug delivery is a route of administration in which patients use an inhaler to inhale their medications and drugs are absorbed into the bloodstream via the lung mucous membrane. This technique is most commonly used in the treatment of lung diseases, for example, asthma and chronic obstructive pulmonary disease (COPD). Different types of inhalers include metered-dose inhalers (MDI), dry powder inhalers (DPI), soft mist inhalers (SMI) and nebulizers. The rate and efficacy of pulmonary drug delivery are affected by drug particle properties, breathing patterns and respiratory tract geometry.
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