DOACs and Heparins Flashcards
Dabigatran - direct thrombin inh
Apixaban, edoxaban, rivaroxaban - direct Xa inh
Benefits of DOACs
Fixed dose
No regular monitoring
Rapid onset (1-4hr)
Half life between 7-14hrs with normal hepatorenal function
Indications for DOAC
Thromboprophylaxis after THR, TKR
Treatment/prevention of recurrent DVT, PE
Prevention of stroke/embolism in non valvular AF with 1+ risk factors
-75+
-DM
-Hx stroke TIA
-HF
HTN
If mechanical valve => warfarin
DOAC
-contraindications
-cautions
CI
Hypersensitivity
Bleeding
-active
-significant risk
-drug interactions
Pregnancy, breastfeeding
Severe liver, kidney impairment
Cautions
-Renal/hepatic impairment
-Older adults
-Low body weight
-Bleeding disorders
-Anaesthesia with postop indwelling catheter
DOAC adverse effects
-common
-less common
Abdo pain
Bruising
Diarrhoea/nausea
Dyspepsia
Dry mouth
Low BP
Rash
Thrombocytopenia
Overlap between DOAC and enox use for VTE management
Confirmed DVT/PE
-apixaban/rivaroxaban -DON’T NEED ENOX
-dabigatran/edoxaban - PRECEDED BY 5 DAYS ENOX
DO NOT GIVE LMWH and DOAC AT THE SAME TIME
DOACs
-initiation
-stopping and antidotes
-switching from VKA to DOAC
-switching from DOAC to VKA
-switching from IV AC to DOAC
Baseline bloods
-FBC
-LFT
-U&E
Antidotes on specialist advice only
Dabigatran - idarucizumab
Apixaban, rivaroxaban - andexanet alfa
Stop if
-severe bleeding occurs
-before surgery
VKA => DOAC
-INR targets depend on the DOAC you’re using
DOAC => VKA
-Give together until INR 2+ => stop DOAC
IV AC => DOAC
-Stop IV AC and start DOAC when next IV dose due
Drug interactions to avoid
IV AC
VKAs unless you’ll be switching from DOAC
AP, NSAIDS
Apixaban
-dosing considerations
-renal and hepatic impairment
-key drug interactions
-how to take
-missed dose
Dose depends on
-indication
-age
-weight
-renal function
Dose reduction if
-80+
-body weight U60
-Creatinine 133+
-prevention of stroke/embolism with CrCl U30
Renal dysfunction
CrCl mild (50-80) or moderate (30-40) => no reduction needed unless if for prevention of stroke/embolism with risk factors above
CrCl severe (U30) => caution
CrCl v severe (U15) => Don’t use
Hepatic dysfunction
Mild/moderate => caution but no dose reduction
Severe, coagulopathy, clinically relevant bleeding risk => CI
Key drug interactions
-systemic antifungals (azoles)
-HIV protease inh
Can take with water, food
If dose missed, take immediately and continue
Dabigatran
-dosing considerations
-renal and hepatic impairment
-key drug interactions
-how to take
-missed dose
Dose reduction needed in THR, TKR if
-CrCl 30-50
-High bleeding risk (75+, verapamil, amiodarone, quinidine)
Dose reduction in stroke/embolism prevention or
DVT,PE Tx Px if
-80+
Renal dysfunction
CrCl mild (50-80) or moderate (30-40) => no reduction
CrCl severe (U30) => CI
IMPORTANT TO MONITOR RENAL ACTIVITY AT BASELINE AND ANNUALLY
Key drug interactions
-systemic antifungals (azoles)
-tacrolimus
Can take with water, food
-TKR, THR - if missed, continue with remaining doses
-Prevention of stroke/embolism in adults with NVAF, treatment/prevent recurrent DVT/PE
-take forgotten dose up to 6hrs before next dose
Edoxaban
-dosing considerations
-renal and hepatic impairment
-key drug interactions
-how to take
-missed dose
Dose reduction
-moderate/severe renal impairment
-U60kg
-use of ciclosporin, dronedarone, erythromycin, ketoconazole
Renal impairment
-mild => NOT NEEDED
-moderate/severe => REDUCTION
-V severe or on dialysis => DON’T USE
IMPORTANT TO MONITOR RENAL AND LIVER ACTIVITY AT BASELINE AND ANNUALLY
Hepatic impairment
-mild/moderate => CAUTION
-severe => DON’T USE
Can take with water, food
If missed, take dose immediately and continue to next day
Rivaroxaban
-dosing considerations
-renal and hepatic impairment
-key drug interactions
-how to take
-missed dose
Dose depends on
-indication
-renal function
Renal impairment
-Severe (THR, TKR thromboprophylaxis) => caution
-Moderate/severe (DVT, PE) => dose reduction
-Moderate/severe (stroke, embolic events) => dose reduction
-Severe (atherothrombotic event prevention after ACS) => caution
-CrCl U15 => DON’T USE
Hepatic impairment
-coagulopathy, clinically relevant bleeding risk => CI
IMPORTANT TO MONITOR RENAL AND LIVER ACTIVITY AT BASELINE AND ANNUALLY
Key drug interactions
-systemic antifungals (azoles)
-AEDs, St Johns Wort
Higher doses must be given with food
Stroke/embolism prevention and VTE prophylaxis THR, TKR
-take missed dose and continue dosing the next day
DVT/PE Tx Px
-initial => ensure that total dose is taken in the day
-maintenance => take missed dose and continue dosing the next day
DOAC key summary
-renal, hepatic impairment
-interaction
Dose adjustments for renal impairment based on CrCl
Not recommended if CrCl U15
Monitor renal function at baseline and annually in older patients
Mild/moderate/severe => BNF as indication will also affect dosing
CI in hepatic disease associated with
-coagulopathy
-clinically relevant bleeding risk
Severe hepatic impairment
Drug CI
-Concomitant AC use unless when switching to warfarin
-meds affecting risk of bleeding
-CHECK BNF
Perioperative management
Minor procedures/low bleeding risk
-restart 6-12hrs postop if no bleeding
Major procedures/high bleeding risk
-restart 48hrs postop if no bleeding
High thrombosis risk
-prophylactic IV AC before DOAC
