Study to compare the metabolic and electrolyte effects of a single oral dose of 320 mg ritobegron administered alone or with a pre- and comedication with bisoprolol, propranolol and acipimox. In addition, to compare the metabolic and electrolyte effects of a single dose of 320 mg ritobegron with those of a single inhalatory dose of 100 μg salmeterol

Inclusion Criteria:

• Healthy male
• Age >= 30 and <= 60 years
• Body Mass Index (BMI) >= 18.5 and <= 29.9 kg/m2
• Signed and dated written informed consent in accordance with Good Clinical Practice and local legislation

Exclusion Criteria:

• Any finding of the medical examination (including blood pressure, pulse rate and ECG) deviating from normal and of clinical relevance
• Gastrointestinal, hepatic, renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders, clinically relevant electrolyte disturbances
• Diseases of the central nervous system (such as epilepsy) or psychiatric disorders or neurological disorders
• History of orthostatic hypotension, fainting spells or blackouts
• Chronic or clinically relevant acute infections
• History of allergy/hypersensitivity (including drug allergy) which is deemed relevant to the trial as judged by the investigator
• Intake of drugs with a long half-life (> 24:00 hours) within at least one month or less than ten half-lives of the respective drug before enrolment in the study or during the study
• Use of any drugs which might influence the results of the trial up to 7 days prior to enrolment in the study or during the study
• Participation in another trial with an investigational drug (within two months prior to administration or during the trial)
• Smoker (> 10 cigarettes or > 3 cigars of > 3 pipes/day)
• Inability to refrain from smoking on trial days
• Alcohol abuse (> 60 g/day)
• Drug abuse
• Blood donation (> 100 mL within four weeks prior to administration or during the trial)
• Any laboratory value outside the reference range if indicative of underlying disease or poor health
• Excessive physical activities within the last week before the trial or during the trial
• Hypersensitivity to treatment medication, salmeterol and/or related drugs of these classes
• Congenital or documented acquired QT- prolongation, previous history of symptomatic arrhythmias
• Systolic BP < 115 mmHg
• Heart rate at rest of > 80 bpm or < 55 bpm
• Any screening ECG value outside of the reference range of clinical relevance including, but not limited to PR interval > 220 ms, QRS interval > 115 ms, QTcB > 420 ms, or QT (uncorrected) > 450 ms
• History of asthma or obstructive pulmonary disease.
• Psoriasis (own medical history or relative)