Choosing the right device and using the right technique are critical when delivering drugs to the lungs.
The administration of inhaled medications is the cornerstone of the treatment of respiratory diseases.1
Proper inhalation technique is essential for effective drug delivery to the lungs; poor technique, resulting in decreased drug exposure, can have significant negative effects on health outcomes and lead to increased burden on the healthcare system.1.2
Metered dose inhalers and dry powder inhalers are the most commonly used respirators.1 However, advancements in technology have led to a plethora of inhaler options. Each device presents its own challenges for correct use, leading to confusion and errors in inhaler technique.3 Up to 90% of people using inhalers may have incorrect technique, regardless of the type of inhaler.1
Types of inhalers
Metered dose inhalers
Pressurized metered dose inhalers (pMDIs) require precise coordination and timing between breathing and actuation for effective drug delivery.4 The inhalation required for pMDI is slow and deep.5 With proper technique, pMDIs deliver approximately 20% of the drug to the lungs, with the remaining 80% remaining in the oropharynx. With incorrect technique, the drug reaching the lungs is reduced, potentially negligible. Spacers with pMDI can improve drug delivery5 allowing finer drug particles more time to reach the lungs and preventing larger drug particles from settling in the oropharynx.
Dry powder inhalers
Dry powder inhalers (DPIs) are breath actuated, meaning the device requires rapid and vigorous inhalation to achieve an effect.ive medicine delivery.4 They do not require hand-breath coordination.6 Although they are a better choice than metered-dose inhalers for people who struggle with breath-actuation coordination, DPIs may be a poor choice for those who cannot inhale forcefully, especially during a respiratory exacerbation. .4
About 12% to 40% of the dose reaches the lungs and about 20% to 25% remains in the DPI device.7 This is due to insufficient particle breakdown or fluctuations in inspiratory flow, humidity and temperature. temperature.
Spacers cannot be used with DPIs.6 Most DPIs should be held horizontally with the vents facing up to prevent spillage of medication. Additionally, IPDs should be stored in a cool, dry place and cleaned with a dry cloth; moisture and water compromise the integrity of the dry particles.
The fine, dry particles of medication are almost odorless and tasteless.6 For this reason, patients may be forced to take another dose by mistake. However, it could be potentially dangerous.
Soft mist inhalers
Soft mist inhalers have an inhalation technique similar to MDIs: deep and slow. However, the slow spray mist requires less coordination than metered dose inhalers.8
Treatment with inhalers
Controller medications are scheduled on a regular basis to control symptoms and reduce the risk of exacerbation.9 Rescue medications are for relief as needed from breakthrough symptoms. It is imperative to distinguish between the two as some patients assume that all inhalers are pain relievers.
Inhaled corticosteroids (ICS) are found in various inhaled formulations and can be used as controllers or as analgesics, depending on the indication.9 Hoarse voice, oral thrush, and upper respiratory tract infections are potential side effects of ICS. Rinsing the mouth after use and spacers help reduce adverse effects of ICS.
Role of the pharmacist
The primary role of the pharmacist is to select the appropriate inhaler for each patient9. Consider availability, cost, and guidelines, as well as the severity of the patient’s illness, preferences, and skills. If possible, avoid using different types of inhalers to avoid confusion.
Demonstrate proper inhalation technique and repeat as necessary (Table9.10). Consider another device if the patient cannot demonstrate skill after repeated training. Check inhaler technique at every opportunity and identify errors using a device-specific checklist. Errors often occur within 4-6 weeks of initial training.11
About the authors
Maria S. Charbonneau, Pharmd, is Clinical Assistant Professor of Pharmacy Practice at Western New England University College of Pharmacy and Health Sciences in Springfield, Massachusetts.
Camille C. Charbonneau, PharmD, BCPS, CDOE, CVDOE, is a clinical pharmacist at CharterCARE Provider Group in Johnston, Rhode Island.
1. Usmani OS, Lavorini F, Marshall J, et al. Critical inhaler errors in asthma and COPD: a systematic review of the impact on health outcomes. Breathe Res. 2018;19(1):10. doi:10.1186/s12931-017-0710-y
2. Almomani BA, Al-Qawashmeh BS, Al-Shatnawi SF, Awad S, Alzoubi SA. Predictors of correct inhaler technique and asthma control in pediatric patients with asthma. Pediatric Pulmonol. 2021;56(5):866-874. doi:10.1002/ppul.25263
3. Haughney J, Price D, Barnes NC, Virchow JC, Roche N, Chrystyn H. Choosing inhalers for people with asthma: current knowledge and outstanding research needs. Breath Med. 2010;104(9):1237-1245. doi:10.1016/j.rmed.2010.04.012
4. Price D, Roche N, Virchow JC et al. Device type and actual efficacy of combination therapy for asthma: an observational study. Breath Med. 2011;105(10):1457-1466. doi:10.1016/j.rmed.2011.04.010
5. Vincken W, Levy ML, Scullion J, Usmani OS, Dekhuijzen PNR, Corrigan CJ. Spacers for inhaled therapy: why use them and how? ERJ Open Res. 2018;4(2):00065-2018. doi:10.1183/23120541.00065-2018
6. How to use a dry powder inhaler (DPI). Allergy and Asthma Network. Accessed June 15, 2022. https://allergyasthmanetwork.org/what-is-asthma/how-is-asthma-treatment/how-to-use-a-dry-powder-inhaler/
7.Labiris NR, Dolovich MB. Lung drug delivery. part II: the role of inhalant delivery devices and drug formulations in the therapeutic efficacy of aerosolized drugs. Br J Clin Pharmacol. 2003;56(6):600-612. doi:10.1046/j.1365-2125.2003.01893.x
8. Using a slow-moving fogger. Allergy and Asthma Network. Accessed June 15, 2022. https://allergyasthmanetwork.org/health-az/chronic-obstructive-pulmonary-disease/how-to-use-a-slow-moving-mist-inhaler/
9. Global Asthma Initiative. Global Strategy for the Management and Prevention of Asthma. Updated 2022. Accessed June 15, 2022. https://ginasthma.org/wp-content/uploads/2022/05/GINA-Main-Report-2022-FINAL-22-05-03-WMS.pdf
10. How to use a standard MDI (pump). National Asthma Board. Updated February 2021. Accessed June 15, 2022. https://www.nationalasthma.org.au/living-with-asthma/how-to-videos/how-to-use-mdi
11. Crompton GK, Barnes PJ, Broeders M, et al; Aerosol Management Improvement Team. The need for improved inhaler technique in Europe: a report from the Aerosol Medication Management Improvement Team. Breath Med. 2006;100(9):1479-1494. doi:10.1016/j.rmed.2006.01.008