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Most patients misused epinephrine autoinjectors, metered-dose inhalers

The majority of patients demonstrated improper usage of epinephrine autoinjectors and metered-dose inhalers, according to recent study results.

The researchers studied 102 adult and pediatric patients who used epinephrine (63% female) and 44 patients (68% female) who utilized metered-dose inhalers (MDIs) with spacers. Patients, enrolled at multiple allergy/immunology clinic sites, demonstrated how they used the device, which was then compared with established standards. Allergen immunotherapy was the primary reason for epinephrine prescription. All patients using MDIs and spacers had asthma.

Eighty-four percent of the epinephrine group did not use the autoinjector correctly, with 56% missing three or more steps in the proper technique. Not holding the unit in place for at least 10 seconds after triggering was the most common error (76%). Failure to place the needle end of the device on the thigh and failure to depress the device deeply enough to activate injection were other common errors.

Ninety-three percent of MDI users failed to demonstrate “perfect technique,” with 63% missing three or more steps. “Exhaling to functional residual capacity or residual volume before actuating the canister” was the most missed step. Failing to realize that a horn-type sound from the spacer indicated the inhaler was performing imperfectly and not shaking the inhaler before administration of the second puff were other mistakes.

Men were more likely to demonstrate correct use of the epinephrine autoinjector (P=.001). Younger patients (P=.05) and those with prior medication education (P=.03) also were more likely to use the autoinjector correctly. Forty-two percent of epinephrine users were prescribed the device less than 1 year before study enrollment.

“We found that the problem of misuse of both epinephrine autoinjectors and MDIs and spacers persists,” the researchers wrote. “Despite the redesign of the devices to promote ease of use, most patients continued to make at least one mistake with the autoinjector. Furthermore, most patients made multiple mistakes and would not have benefited from self-administration of the potentially life-saving treatment if the need arose.”

Disclosure: The researchers report no relevant financial disclosures.