Which LMWH requires renal dose adjustment when CrCl <30 mL/min?

• A. Enoxaparin
• B. Dalteparin
• C. Fondaparinux
• D. Heparin

Answer: (A)

Renal clearance dictates how these anticoagulants behave in kidney impairment. Enoxaparin is cleared predominantly by the kidneys, so when CrCl drops below 30 mL/min, the drug can accumulate and anti-Xa activity rises, increasing bleeding risk. Because of this, the dose often needs to be reduced or a switch to unfractionated heparin is considered in severe renal impairment.

Dalteparin, by contrast, has less reliance on renal clearance, so dose adjustments at CrCl <30 mL/min are not routinely required in many regimens (though clinical judgment and monitoring may apply). Fondaparinux is not an LMWH and is also renally cleared, with contraindication or avoidance in CrCl <30 mL/min due to accumulation risk. Unfractionated heparin does not require renal-dose adjustment and is generally used when renal function is severely compromised.