Which anticoagulant medication is routinely administered during hemodialysis to prevent clot formation in the extracorporeal circuit?

Heparin (unfractionated heparin) is routinely administered intravenously during hemodialysis sessions to prevent clotting within the dialyzer and extracorporeal blood circuit. Heparin activates antithrombin III, which inhibits thrombin and factor Xa. The effect is reversible and short-acting. This is important in dentistry because patients undergoing dialysis may have elevated bleeding risk on the day of dialysis (due to residual heparin effect) — dental procedures are ideally scheduled the day after dialysis.