The investigators will compare plasma kinetics of two marker drugs in individuals with different genetic variations in the MDR1-gene. The hypothesis is that one group will have higher exposure than the other.

Inclusion Criteria:

• - Healthy volunteer ≥ 18 years of age
• Normal kidney function as measured by GFR according to Cockroft-Gault (70-120 ml/min)
• Normal P-potassiumvalue (3,6-4,6 mmol/L)
• HF>50 and no AV-block on resting ECG. No other significant abnormalities as judged by the investigator.
• Subject giving written informed consent
• Subject capable of understanding instructions

Exclusion Criteria:

• - Pregnancy
• Ongoing infection
• Intake of medication, including natural remedies (for example St John´s wort), within one month prior to starting study except for paracetamol.
• Active drug or alcohol abuse