Figure 4.

Formation clearance (CLf) for tolbutamide and midazolam with and without dicloxacillin. CL_f was calculated as: Amount of metabolite in urine_0–t/AUC of substrate_0–t, where AUC is the area under the plasma concentration–time curve and t is time. One cytochrome P450 m(CYP) 2D6 poor metabolizer was excluded from the dextromethorphan graph, to avoid clustering of the remaining individuals. Two individuals were excluded from the caffeine analysis owing to ingestion of caffeine during the study. Dashed lines represent CYP2C9 poor metabolizers for tolbutamide and CYP2C19 ultrarapid metabolizers for omeprazole