1. Holy Family Hospital, Rawalpindi, Pakistan
2. Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institute, Karolinska University Hospital Huddinge, SE-141 86, Stockholm, Sweden
3. Strathclyde Institute of Pharmacy & Biomedical Sciences, Strathclyde University, Glasgow G4 ORE, UK
4. National Institute of Health, Islamabad, Pakistan