Anticoagulants Flashcards
MOA Heparin, enoxaparin
Interacts with antithrombin III to inhibit factors Xa and thrombin
Reversal heparin, enoxaparin
Protamine sulfate, Inactivates heparin via ionic compound formation
MOA Warfarin
Inhibits vitamin K activation, indirectly decreasing coagulation factor synthesis
Reversal warfarin
Vitamin K and prothrombin complex concentrate or FFP
Restores deficient vitamin K and vitamin K-dependent coagulation factors II, VII, IX, and X
MOA Dabigatran
Directly inhibits thrombin (factor IIa)
Reversal dabigatran
Idarucizumab, Binds and inhibits dabigatran at its active site
MOA Rivaroxaban, apixaban
Directly inhibit factor Xa
Reversal rivaroxaban, apixaban
Andexanet alfa, Binds apixaban or rivaroxaban as a decoy factor Xa molecule
**Andexanet alfa is not approved for the reversal of other factor Xa inhibitors (eg, edoxaban).
IV Heparin neuraxial guidelines
Hold before procedure: until PTT <40, usually 4-6 hours
Restart after procedure: 1 hour (if bloody tap, discuss!)
Hold before catheter removal: 4-6h from last dose and confirm PTT <40
Restart after catheter removal: 1 hour - with frequent neuro checks
Half life of heparin
1-2 hours
SC heparin 5000 U BID/TID neuraxial guidelines
Hold pre-proc: 4-6h or PTT <40
Restart post-proc: no delay
Hold pre cath removal: 4-6h
Restart post cath removal: no delay
SC heparin 7500-10000 U BID (<20,000 U per day) neuraxial guidelines
Hold pre-proc: 12h & PTT <40
Restart post-proc: avoid while catheter in place
Hold pre cath removal: avoid while catheter in place
Restart post cath removal: 12h & perform neuro checks
SC heparin >20k U daily neuraxial guidelines
Hold pre-proc: 24h & check PTT <40
Restart post-proc: assess individual case, monitor neuro checks
Hold pre cath removal: “ “
Restart post cath removal: “ “
Warfarin neuraxial guidelines
Hold pre-procedure: 5 days or INR =< 1.2, may be within 24 hours if single dose
Restart post-proc: no delay
Hold pre cath removal: INR <1.5 may remove; INR 1.5-3.0 maintain with caution and frequent neuro checks; INR >3.0 hold warfarin dose while catheter in place
Restart post cath removal: neuro checks x24h
Warfarin half life
20-60 hours
LMWH therapeutic dosing: enoxaparin, dalteparin, tinzaparin
Enox: 1 mg/kg SC BID or 1.5mg/kg QD
Dalt: 120u/kg BID or 200u/kg QD
Tinz: 175 u/kg QD
LMWH therapeutic dosing neuraxial guidelines
Hold pre-proc: 24h, consider checking anti-Xa in elderly/renal insufficiency
Restart post-proc: 24-72h (earlier if lower bleeding risk surgery, later if higher risk of bleeding) - if bloody tap, consider holding >24h
Hold pre cath removal: remove catheter before initiating LMWH
Restart post cath removal: minimum 4 hr, & at least 24h after initial cath placement
LMWH half life
4-7 hours
LMWH prophylactic dosing neuraxial guidelines
Hold pre-proc: minimum 12 hours
Restart post-proc: 12 hours
Hold pre cath removal: avoid
Restart post cath removal: 4 hr, at least 12h since initial placement (except in OB may restart 6-12h as long as catheter out for 4 hr and was not traumatic - if traumatic then 24h)
Fondaparinux neuraxial guidelines
Hold pre-proc: RAS has no recommendation; for pain hold 4 days
Restart post-proc: avoid
Hold pre cath removal: avoid with catheter
Restart post cath removal: 6 hours
*Consider holding longer in renal impairment; contraindicated in CrCl <30ml/min or Child-Pugh C hepatic failure
Fondaparinux half life
17-21 hours
Rivaroxaban neuraxial guidelines
Hold pre-proc: 72 hours
Restart post-proc: 6h, avoid with catheter
Hold pre cath removal: 22-26 hours
Restart post cath removal: 6 hours unless traumatic - then discuss
*Consider holding longer in renal impairment; contraindicated in CrCl <15ml/min or Child-Pugh C hepatic failure
Rivaroxaban half life
5-9 hours
Apixaban neuraxial guidelines
Hold pre-proc: 72 hours
Restart post-proc: 6 hr, avoid if catheter
Hold pre cath removal: 26-30 hours
Restart post cath removal: 6 hr unless traumatic - then discuss
*Consider holding longer in renal impairment; contraindicated in CrCl <15ml/min or Child-Pugh B or C hepatic failure
