[1] Univ Houston, Coll Pharm, Houston, TX 77030 USA
[2] Singapore Gen Hosp, Dept Pharm, Singapore 169608, Singapore
[3] Singapore Gen Hosp, Dept Internal Med, Div Infect Dis, Singapore 169608, Singapore
[4] Singapore Gen Hosp, Dept Anaesthesia & Surg Intens Care, Singapore 169608, Singapore