tokens: RESULTS : Unexpectedly high concentrations of argatroban were measured in these samples ( range , 0 - 32 microg / mL ) , and a prolonged plasma argatroban half life ( t ( 1 / 2 ) ) of 514 minutes was observed ( published elimination t ( 1 / 2 ) is 39 - 51 minutes [ < or = 181 minutes with hepatic impairment ] ) .