The pressurized metered-dose inhalers familiar to people with asthma and other respiratory problems are frequently not used in the right way, and this is also the case with the newer dry powder inhalers, Italian researchers report.

“It is known that many patients using pressurized metered-dose inhalers have a poor inhalation technique, which possibly reduces the drug delivery to the lung,” Dr. Andrea S. Melani told Reuters Health. “We have shown that in real life, many experienced patients were also using newer dry powder inhalers with a similar percentage of critical errors.”

Melani, at the Azienda Ospedaliera Senese in Siena, and colleagues note that manufacturers have claimed that dry powder inhalers are easier to use than earlier devices because they do not require breathing to be coordinated with actuating the inhaler. Studies appear to confirm the claim.

To determine if this is also true in practice, the researchers evaluated the inhalation technique of 1404 outpatients, most of whom had asthma or chronic obstructive pulmonary disease such as emphysema.

As reported in the Annals of Allergy Asthma and Immunology, about half of the participants most often used a traditional metered dose inhaler, while the others used a dry powder inhaler - that is, the Aerolizer inhaler, the Turbuhaler, or the Diskus inhaler.

Melani’s group found that 24 percent of pressurized metered-dose inhalers users did so poorly. However, only 3 percent of those who used the inhaler in conjunction with a spacer used the device incorrectly.

Failure to use the correct technique was seen in 17 percent of Aerolizer Inhaler users. For the Turbuhaler, the proportion was 23 percent, and for the Diskus it was 24 percent.

Summing up, Melani noted that “education, and not simply changing to the newer dry powder inhalers without adequate training, is the best strategy for minimizing key errors when inhalers are used.”

SOURCE: Annals of Allergy Asthma and Immunology, November 2004.