1. Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska University Hospital-Huddinge C-168, Karolinska Institute, Stockholm, Sweden.
2. Department of Pharmacology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
3. Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
4. Department of Clinical Pharmacology, Muhimbili University of Health and Allied sciences, Dar es Salaam, Tanzania.
5. Department of Internal Medicine, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
6. Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany.
7. Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Freiburg, Freiburg, Germany.