Author : Joana Simões (pharmacist ) Inhalers are devices that allow medicines to be administered through the mouth, delivering them directly to the airways and lungs , where they are intended to act. This direct action at the site of effect has several advantages: It ensures faster therapeutic efficacy; It allows the use of lower doses of medicine compared with other routes of administration. They are essential in the treatment of many respiratory diseases, such as: Asthma; Chronic obstructive pulmonary disease (COPD). Main types of inhalers There are three main types of inhalers, which differ mainly in the way the medication is released (aerosol, powder or mist) and in the need for coordination between dose release and inhalation. It is essential to learn the correct inhaler technique and to clarify any questions with healthcare professionals. The effectiveness of the medication depends on correct inhaler use. Common errors include inadequate inhalation, lack of coordination or absence of post-inhalation breath-holding. Pressurised metered-dose inhalers (pMDI) The medicine is released as an aerosol (or spray); They use a propellant gas mixed with the medicine in a pressurized container; When the device is pressed, a dose of medicine is released (a puff or dose); They require coordination between activation and inhalation; They are widely used for bronchodilators and corticosteroids. Dry powder inhalers (DPI) The medicine is released as a dry powder; It depends on a fast and forceful inhalation flow to release the medication from its container; They are widely used for bronchodilators and corticosteroids; There are different devices, with their own mechanisms for preparing the dose and from different brands (for example, Diskus and Turbohaler ), whose names are often used to refer to inhalers. Soft mist inhalers (SMI) The medicine is released as a fine mist that forms slowly and is easy to inhale; They do not depend as much on inspiratory effort and are therefore more suitable for patients with lower inspiratory capacity or difficulty coordinating dose activation with inhalation; Respimat is an example of this type of inhaler; it is a brand whose name is sometimes used to refer to soft mist inhalers. Inhaler storage Inhalers should be stored at room temperature (between 15°C–25°C), away from heat sources or direct light. They should not be exposed to humidity , especially dry powder inhalers (DPI), and therefore should not be left or stored in bathrooms or kitchens, which are the most humid areas in a home. They should be protected from extreme cold because very low temperatures may affect dose delivery, particularly in pressurized metered-dose inhalers (pMDI). They should be protected from mechanical shock that may damage the device and interfere with the medicine release mechanism. They should be kept clean, without contact with water , always following the instructions in the patient information leaflet and the guidance provided by healthcare professionals. Environmental impact and good practices for inhaler use and disposal Healthcare can also contribute to greenhouse gas emissions , and inhalers are part of this reality. Pressurized metered-dose inhalers (pMDI) have a higher carbon footprint due to the propellant gases (hydrofluoroalkanes or HFA) released during their use and disposal. In comparison, dry powder inhalers (DPI) and soft mist inhalers (SMI) have a significantly lower environmental impact because they do not use propellant gas. The choice of inhaler is always based on the patient’s clinical needs and must be individualized. Not all inhalers are equivalent, and not all patients are able to use every type of inhaler correctly. Therefore, environmental impact should never compromise treatment effectiveness or safety. There are good practices that inhaler users should adopt , many of which are also important for protecting the environment: Follow the instructions for use of the specific device you are using , as described in the patient information leaflet. Whenever necessary (or periodically), ask a doctor or pharmacist for support to review your inhalation technique. Avoid accumulating unnecessary devices by checking the remaining doses before discarding an inhaler and purchasing new ones. Always check the number of doses remaining before travelling , ensuring you have enough medication for the entire trip. Carry inhalers in your hand luggage, along with a prescription or medical report if needed . Never dispose of an inhaler in household waste or standard recycling bins. Return used or expired inhalers to pharmacies through appropriate collection systems , allowing proper waste management and material recovery. Correct use of inhalers is essential to control respiratory diseases, but also to avoid waste and reduce environmental impact. Source: British Thoracic Society. Environmental impact of inhalers and sustainability in respiratory care. 2021. Fundación SIGRE. Gestión de envases y residuos de medicamentos. 2023. Sociedad Española de Farmacia Hospitalaria. Inhaladores y salud del planeta. 2022. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
