Influence Of Different Airflow Resistances On Drug Effect Of 50μg Salmeterol And 6 μg Formoterol

Single-Centre Randomised Open Crossover Study to Examine the Influence of Different Internal Resistances of Discus and Turbohaler Respectively on the Effects of Salmeterol and Formoterol in Asthmatic Subjects

Effect of inhaled drugs administered as dry powder is not only dependent on drug efficacy but also on technical properties of the inhalers. Different inhalers have different internal resistances and therefore it is expected that patients with limited airflow may have different exposure rates of drugs delivered from different devices

Inclusion criteria:

• Asthma Reversibility >15% and 200 ml in total FEV1 <85% of normal

Exclusion criteria:

• Smoking history >20 pack years Treatment with ICS >500μg Fluticasone or aquivalent in the last 4 weeks Asthma exacerbation in the last 4 weeks