Investigation of the bioavailability of linagliptin after concomitant multiple oral administration of 5 mg linagliptin tablets and 600 mg rifampicin (Treatment A) in comparison to multiple oral administration of 5 mg linagliptin tablets given alone (Treatment B)

Inclusion Criteria:

• Healthy males and females according to the following criteria: Based upon a complete medical history, including the physical examination, vital signs (Blood Pressure (BP), Pulse Rate (PR)), 12-lead Electrocardiogram (ECG), clinical laboratory tests
• Age 18 to 50 years (incl.)
• BMI 18.5 to 29.9 kg/m2 (incl.)
• Signed and dated written informed consent prior to admission to the study in accordance with Good clinical practice (GCP) and the local legislation

Exclusion Criteria:

• Any finding of the medical examination (including BP, PR and ECG) deviating from normal and of clinical relevance
• Any evidence of a clinically relevant concomitant disease
• Gastrointestinal, hepatic (incl. porphyrias), renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders
• Surgery of the gastrointestinal tract (except appendectomy)
• Diseases of the central nervous system (such as epilepsy) or psychiatric disorders or neurological disorders
• History of relevant orthostatic hypotension, fainting spells or blackouts.
• Chronic or relevant acute infections
• History of relevant allergy or hypersensitivity (including allergy to drug or its excipients)
• Intake of drugs with a long half-life (more than 24 hours) within at least one month or less than 10 half-lives of the respective drug prior to administration or during the trial
• Participation in another trial with an investigational drug within two months prior to administration or during the trial
• Smoker (more than 10 cigarettes or more than 3 cigars or more than 3 pipes/day)
• Inability to refrain from smoking on trial days
• Alcohol abuse (more than 30 g/day if male, more than 20 g/day if female)
• Drug abuse
• Blood donation (more than 100 mL within four weeks prior to administration or during the trial)
• Excessive physical activities (within one week prior to administration or during the trial)
• Any laboratory value outside the reference range that is of clinical relevance
• Inability to comply with dietary regimen of trial site
• Thrombocytopenia or increased liver function tests (i.e. Alanine transaminase (ALT), Aspartate transaminase (AST), bilirubin, Alkaline phosphatase (AP), Gamma-glutamyl transferase (GGT)) at screening
• prior rifampicin exposure

For female subjects:

• Positive pregnancy test, pregnancy or planning to become pregnant during the study or within 2 months after study completion
• No adequate contraception during the study and until 1 month after study completion, i.e. not any of the following: IUD (intrauterine device), sexual abstinence for at least 1 month prior to enrolment, vasectomised partner (vasectomy performed at least 1 year prior to enrolment), or surgical sterilisation (including hysterectomy). Females, who do not have a vasectomised partner, are not sexually abstinent or surgically sterile have to use an additional barrier method (e.g. condom, diaphragm with spermicide)
• Lactation