Median -LSB- interquartile range -RSB- efavirenz concentrations were @,@ ng/mL -LSB- @,@-@ ,@ -RSB- , @,@ ng/mL -LSB- @,@-@ ,@ -RSB- and @,@ ng/mL -LSB- @,@-@ ,@ -RSB- at week +@ , week +@ , week @ , respectively , and @,@ ng/mL -LSB- @,@-@ ,@ -RSB- at week @ .