Pharmacodynamic/Pharmacokinetic Interactions Between Oral Roflumilast and Inhaled Formoterol

Inclusion Criteria: * Age between 18 and 45 years * Normal body weight as indicated by a Body Mass Index (BMI) between 18 and 30 kg/m2 and a body weight \> 50 kg * Assessed as healthy, based on a screening examination including medical history, physical examination, BP, PuR, ECG, and clinical laboratory results * Caucasian Exclusion Criteria: * Suspected lack of compliance * Participant in any other study or donation of blood during the last 30 d before start of this study (last day of intake of medication - first day of medication in the following study) * Any active disease, acute or chronic (also psychiatric diseases) * Any signs or present history of cardiac diseases (e.g. QTc interval acc. to Bazett ≥ 430 ms, PQ ≥ 220 ms), in particular tachycardiac arrhythmia, third-degree AV-block, idiopathic-subvalvular aortic stenosis or hypertrophic-obstructive cardiomyopathia * Proneness to symptomatic orthostatic dysregulation, fainting or "blackouts" (medical history), or to orthostatic hypotension defined by SBP \< 90 mm Hg (standing blood pressure, 30 s after raising up from a supine position) * Gastrointestinal surgery except from appendectomy and herniotomy * HIV or hepatitis screening positive or not performed (in case of a positive HIV test, the subject had to be informed by a physician in personal communication * Drug screening positive or not performed * Excessive xanthine consumption (more than 5 cups of coffee or equivalent per day) * Non-compliance for measurements of impedance cardiography (feasibility was proven and documented at the screening visit by one test procedure)