Plasma stavudine concentrations vs time after dose, collected during OGTT in 47 HIV-1 infected participants. OGTT = oral glucose tolerance test, d4T = stavudine. The solid line indicates the median predicted concentrations and the dashed lines the 90% prediction interval of a model developed using rich stavudine concentration-time data. The lower limit of quantification (20 ng/mL) is shown by a dotted line. Open circles indicate stavudine concentrations when stavudine was taken before the OGTT, and the solid diamonds are stavudine concentrations collected when the stavudine dose was taken during the OGTT (i.e. the 0-hour OGTT was collected pre-dose).