Which statement accurately describes enoxaparin (a low molecular weight heparin)?

• A. Requires routine lab monitoring
• B. LMWH with no lab monitoring and reversible with protamine sulfate
• C. Direct thrombin inhibitor
• D. Dissolves clots quickly

Answer: (B)

Enoxaparin is a low molecular weight heparin, which has more predictable pharmacokinetics than unfractionated heparin. Because of this, it typically does not require routine lab monitoring to gauge its effect. Its anticoagulant action comes from binding to antithrombin III and preferentially inhibiting factor Xa (with less effect on thrombin), which reduces the generation of thrombin and slows clot formation rather than dissolving clots. It is not a direct thrombin inhibitor and it does not actively dissolve existing clots—that role belongs to thrombolytics. Protamine sulfate can reverse its effect, though reversal is not as complete as with unfractionated heparin; nevertheless, reversal with protamine is considered effective in many clinical scenarios. This combination of no routine monitoring and the option for reversal with protamine makes the statement describing enoxaparin as having no routine lab monitoring and being reversible with protamine sulfate the most accurate.