Rivaroxaban
Chemical
Competitive IRREVERSIBLE inhibitor of Xa (free & blot bound)
Use
- Reduce embolic events in AF
- Prevent DVT post ortho
- Rx DVT/PE
Presentation
Tablets; 2.5 – 10mg
Dose
AF 20mg OD
DVT 15mg BD for 21d → 20mg OD
DVT prophylaxis 10mg OD
Route
PO
Onset / DoA
30 mins → max 2hrs → t ½ B 16hrs → offset of anticoagulation in 24hrs
MoA
- Direct competitive REVERSIBLE inhibition Xa
- ↓THROMBIN formation & effects of thrombin
PK
A
80 – 100% OBA
D
VD 50L
Very high PPB 95% ∴ not dialysable
M
Metabolised by liver enzymes
P450 3A4
No active metabolites
E
66% by kidneys
- 50:50 inactive/active
- Rest = faecal biliary route
Adverse Effects
- Haemorrhage
- Drug Interactions → CYP3A4 inhibitors (ketoconazole) → will ↑ [ ]
- Other anticoag should be avoided
Monitoring
Anti-Xa-levels
→ Sold as no-monitoring required, but you need to monitor to assess PD in high risk patients (high age, low weight, low renal function)
→ NB: anti-Xa levels measure the drug [ ], not the anticoagulant activity
Reversal
Highly PPB → not dialysable
PROTHROMBIN-VF (II, IX, X, some V & VII)
?ANDEXXA = recombinant Xa coming out?
Haem consult
(effects wear off in 24hrs)