Many people with asthma or emphysema could be taking their inhaled medicines incorrectly, researchers say.

When they asked 100 adults hospitalized for asthma or a lung disease like emphysema to show how they used their inhalers at home, most made some type of mistake.

Fortunately, it wasn’t hard for them to learn the correct methods.

Overall, patients misused metered-dose inhalers nearly nine out of 10 times, and Diskus inhalers seven out of 10 times, the researchers report in the Journal of General Internal Medicine.

Both types of inhalers deliver medication directly to the airways. Diskus inhalers are used mainly for “controller” medications - the ones patients take regularly to keep asthma or other lung disease symptoms under control. Metered-dose inhalers can be used for controller or “rescue” medications, which patients take during severe episodes of breathlessness and other symptoms.

The two types of inhalers work by different mechanisms, and require different steps to deliver the medication to the lungs.

So for people who use both - which is quite common - the ins-and-outs of correct use can be particularly tricky, said lead researcher Dr. Valerie G. Press of the University of Chicago. With metered-dose inhalers, people have to inhale slowly, for example, while the Diskus device requires a sharp inhalation.

“Respiratory inhalers require multiple coordinated steps,” Press told Reuters Health. “They are not just point-and-shoot.”

Ideally, people who use inhalers should bring them to their doctor appointments and demonstrate how they use the devices at home, Press noted. But in reality, that may not happen.

“The key for patients is, don’t assume that inhalers should be easy to use, and don’t be afraid to ask questions,” Press said.

The 100 patients in the study were at one of two Chicago hospitals because of serious asthma or worsening of their chronic obstructive lung disease, or COPD. COPD is the medical term for disease that blocks the flow of air in and out of the lungs.

Some of the patients, Press said, were hospitalized due to near-fatal complications - making it especially critical that they know how to properly use their inhalers.

When the researchers asked everyone to demonstrate how they used their inhalers at home, one of the biggest problems was that patients failed to breathe out fully before placing the inhaler in the mouth.

One of the obstacles, Press and her colleagues found, appeared to be vision problems. Nearly all patients with poor vision used the Diskus inhaler incorrectly, compared with slightly more than half of those with adequate vision.

It might be that vision problems make it harder for people to read the inhalers’ instructions, which are typically written in very small letters, Press said.

On the bright side, though, the researchers also found it didn’t take much to improve people’s inhaler use.

Forty-two participants were given one or two lessons on how to use the devices, which included having them “teach” the techniques back to the researchers. All were able to master the techniques for both inhalers.

“In general,” Press said, “it’s very important for people to know how to use their medications properly.”

For people with asthma or COPD, she said, trouble controlling symptoms might be a sign the inhaler isn’t being used correctly, and they should ask their doctor to evaluate how they’re using it.

SOURCE: Journal of General Internal Medicine, online January 20, 2011.