INHALATION TECHNIQUE AND VARIABLES ASSOCIATED WITH MISUSE OF CONVENTIONAL METERED-DOSE INHALERS AND NEWER DRY POWDER INHALERS IN EXPERIENCED ADULTS

The use of Dry Powder Inhalers (DPI’s) has increased substantially in the past 4 years. Manufacturers claim the primary advantage of DPI’s to be that they are breath-activated, so coordination of inhalation and actuation is not required. However, DPI’s still require a number of essential steps to be performed correctly in order for patients to receive reliable drug delivery.

A multicenter, observational survey was conducted to assess the inhalation technique and variables associated with the misuse of pressurized metered dose inhalers (pMDI’s) and new DPI’s in clinical practice. The study, “Inhalation technique and variables associated with misuse of conventional metered-dose inhalers and newer dry powder inhalers in experienced adults” evaluated the inhalation technique in 1404 experienced outpatients suffering mainly from Asthma and COPD in 20 respiratory centers. The patients demonstrated their inhalation technique to the investigator using pMDI’s, pMDI’s in conjunction with large volume spacers, and DPI’s, along with a placebo inhaler.

The results showed that the pMDI used in conjunction with a valved holding chamber showed the smallest percentage of critical errors – 3%. In contrast, 24% of patients failed to correctly perform essential steps for reliable lung delivery when using pMDI’s alone and 22.8% when using DPI’s (Aerolizer Inhaler** – 17%, Turbuhaler** – 23%, Diskus** – 24%).

The study concluded that the best strategy for minimizing poor inhalation technique is the addition of a valved holding chamber to a pMDI in combination with education from health care personnel.

This in-vivo study highlights the fact that there are major flaws in patient compliance associated with the use of dry powder inhalers. In addition, it underscores the effectiveness of using a valved holding chamber in conjunction with a pMDI when administering aerosol medications to all patient populations.

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MD-198A-0105