Choosing the appropriate device and using the correct technique are critical for drug delivery to the lungs.
Inhaled drug delivery is the cornerstone of respiratory disease treatment.1
Proper inhaler technique is critical for effective drug delivery to the lungs; improper technique, resulting in decreased drug exposure, can significantly affect health outcomes negatively and lead to increased health care system burden.1,2
Pressurized meter dose inhalers and dry powder inhalers are the most used respiratory devices.1 However, technology advances have led to a plethora of inhaler options. Each device presents its own challenges for proper use, resulting in confusion and errors in inhaler technique.3 Up to 90% of individuals using inhalers may have incorrect technique, regardless of inhaler type.1
Pressurized metered-dose inhalers
Pressurized metered-dose inhalers (pMDIs) require coordination and precise timing between breath and actuation for effective drug delivery.4 The inhalation required for pMDIs is slow and deep.5 With proper technique, pMDIs deliver approximately 20% of drug to the lungs, with the remaining 80% or so staying in the oropharynx. With incorrect technique, the drug reaching the lungs is reduced, potentially to negligible. Spacers with pMDIs may improve medication delivery5 by allowing more time for finer drug particles to reach the lungs and filtering larger drug particles from depositing in the oropharynx.
Dry-powder inhalers (DPIs) are breath actuated, meaning that the device requires a forceful, rapid inhalation for effective drug delivery.4 They do not require hand-breath coordination.6 Although a better choice than MDIs for individuals struggling with breath/actuation coordination, DPIs may be a poor choice for those who cannot inhale forcefully, especially during a respiratory exacerbation.4
Approximately 12% to 40% of the dose reaches the lungs, and approximately 20% to 25% remains in the DPI device.7 This is because of insufficient particle disaggregation or inspiratory flow rate, humidity, and temperature fluctuations.
Spacers cannot be used with DPIs.6 Most DPIs must be held horizontally with vents upward to prevent medication dumping. Additionally, DPIs must be stored in a cool, dry place and cleaned with a dry cloth; humidity and water compromise the integrity of the dry particles.
The dry, fine drug particles are nearly odorless and tasteless.6 Because of this, patients may be compelled to take another dose erroneously. However, this could be potentially dangerous.
Soft-mist inhalers have a similar inhalation technique to MDIs: deep and slow. However, the slow-moving mist spray requires less coordination than MDIs.8
Treatment With Inhalers
Controller medications are scheduled on a routine basis to control symptoms and reduce exacerbation risk.9 Reliever medications are for as-needed relief of breakthrough symptoms. It is imperative to distinguish the two because some patients assume all inhalers are relievers.
Inhaled corticosteroids (ICS) are found in various inhaled formulations and can be used either as controllers or relievers, depending on the indication.9 Hoarse voice, oral candidiasis, and upper respiratory tract infections are potential adverse effects of ICS. Rinsing the mouth after use and spacers help reduce ICS adverse effects.
The pharmacist’s foremost role is to choose the appropriate inhaler device for each patient.9 Consider availability, cost, and guideline directives, as well as patient illness severity, preference, and skills. When possible, avoid use of differing inhaler types to avoid confusion.
Demonstrate proper inhaler technique and repeat as necessary (Table9,10). Consider another device if the patient cannot demonstrate proficiency after repeated trainings. Check inhaler technique at every opportunity, and identify errors using a device-specific checklist. Errors often occur within 4 to 6 weeks of initial training.11
About The Authors
Maria S. Charbonneau, PharmD, is a 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 impact on health outcomes. Respir 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 proper inhaler technique and asthma control in pediatric patients with asthma. Pediatr 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 inhaler devices for people with asthma: current knowledge and outstanding research needs. Respir 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 real-world effectiveness of asthma combination therapy: an observational study. Respir 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. Spacer devices 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 & Asthma Network. Accessed June 15, 2022. https://allergyasthmanetwork.org/what-is-asthma/how-is-asthma-treated/how-to-use-a-dry-powder-inhaler/
7. Labiris NR, Dolovich MB. Pulmonary drug delivery. part II: the role of inhalant delivery devices and drug formulations in therapeutic effectiveness of aerosolized medications. Br J Clin Pharmacol. 2003;56(6):600-612. doi:10.1046/j.1365-2125.2003.01893.x
8. Using a slow-moving mist inhaler. Allergy & Asthma Network. Accessed June 15, 2022. https://allergyasthmanetwork.org/health-a-z/chronic-obstructive-pulmonary-disease/how-to-use-a-slow-moving-mist-inhaler/
9. Global Initiative for Asthma. Global strategy for asthma management and prevention. 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 (puffer). National Asthma Council. 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 Drug Management Improvement Team. The need to improve inhalation technique in Europe: a report from the Aerosol Drug Management Improvement Team. Respir Med. 2006;100(9):1479-1494. doi:10.1016/j.rmed.2006.01.008