Enoxaparin - At what level of APTT clexane should be stopped?

The aPTT level is not the test you should be using to determine enoxaparin levels. There is a high degree of variability in aPTT readings from one laboratory to another, and even from one reagent to another. Given that several biologic factors can influence the aPTT independent of the effects of LMWH, institutions should be transitioning to monitoring enoxaparin with antifactor Xa levels, rather than the aPTT or PT. The peak and trough levels of about 1.2 and 0.52 IU/mL, respectively are typical of the steady state range. Based on enoxaparin sodium pharmacokinetics, this difference in steady state is expected and within the therapeutic range.