SELECTED ARTICLES FROM THE RECENT LITERATURE 2005

12/12/05

Cumulative effects of formoterol administered by a dry powder inhaler

Summary
Background - Formoterol (Form), a long acting beta agonist, has the added advantage of a rapid onset of bronchodilating effect, as rapidly as does albuterol. Thus, it has been recommended that Form can also be used as a rescue medication in acute asthma attacks. Dry powder inhalers (DPI) have the potential advantage of being breath activated (not requiring timing of manual activation with inspiration). However, most DPI devices such as the Aerolizer require loading single doses at a time.

Findings - Randell et al of Kuopio Hospital in Finland compared the effects of escalating doses of Form delivered by: 1) Aerolizer or 2) Easyhaler, a recently developed multidose DPI in 35 asthmatic adults.

They found similar patterns of dose dependent bronchodilating effects with the Aerolizer and Easyhaler administration. The occurrence of adverse effects was dose related, mainly tremor, headache, palpitation and slight decreases in the serum K+ levels. The heart rate increased significantly more following the Aerolizer than after the Easyhaler delivery of Form.

The authors concluded that Form delivered by the Easyhaler was as safe as Form delivered by an Aerosolizer and more convenient to use.

Reference
Respir Med 2005;99:1485-93

Editor's Comments
These findings in this study are helpful in that the cumulative doses of Form administered was 96 microg (equivalent to 8 puffs of Form) relevant to what might be needed during repeated treatments for acute asthma exacerbations. The onset of Form action is within a few minutes with peak effects generally present by 2 hours.

One would have liked to see a comparison of Form delivery by the 2 DPI devices by a pressurized MDI with a holding chamber. Some studies have shown as much efficacy by this MDI delivery system without the need for timing activation with inspiration.

 

<-- BACK