Table. Characteristics of oral anticoagulants.
| Warfarin | Apixaban | Dabigatran | Rivaroxaban | |
|---|---|---|---|---|
| Brand | Coumadin, Marevan | Eliquis | Pradaxa | Xarelto |
| Licensed indications | AF, VTE, valvular heart disease | AF, VTE | AF | AF, VTE |
| Dosing frequency | daily | twice daily | twice daily | Daily † |
| Oral bioavailability ‡ | 100% | 50% | 7% | >80% § |
| Excretion unchanged in urine ‡ | 0% | 34% | 80% | 36% |
| Major metabolic/transport pathways | CYP2C9 | CYP3A4, P-glycoprotein | P-glycoprotein # | CYP3A4, P-glycoprotein |
| Drug half-life ¶ | ||||
| healthy young individuals | 40 hours | 10 hours | 14 hours | 7 hours |
| chronic kidney disease | ||||
| moderate | not reported | not reported | 19 hours | 9 hours |
| severe | – | – | 28 hours | 10 hours |
| chronic liver disease | ||||
| moderate | not reported | not reported | 12 hours | 10 hours |
| severe | – | – | not reported | not reported |
| Effect of chronic disease on anticoagulant concentrations ** | ||||
| chronic kidney disease | ||||
| moderate | not reported | 30% increase | 210% increase | 50% increase |
| severe | – | 40% increase | 530% increase | 60% increase |
| chronic liver disease | ||||
| moderate | not reported | 9% increase | 6% decrease | 120% increase |
| severe | – | not reported | not reported | not reported |
| Effect of concomitant drugs on anticoagulant concentrations †† | Amiodarone increases anticoagulant | Erythromycin increases anticoagulant | Verapamil increases anticoagulant | Erythromycin increases anticoagulant |
| Rifampicin decreases anticoagulant | Rifampicin decreases anticoagulant | Rifampicin decreases anticoagulant | Rifampicin decreases anticoagulant | |
AF atrial fibrillation
VTE venous thromboembolism
CYP cytochrome P450
All values are means.
† Initial dosing in normal renal function is twice daily, maintenance dose is once daily.
‡ Values in healthy young individuals.
§ When administered with food (when fasting, the oral bioavailability of rivaroxaban 20 mg is 66%).
# Dabigatran etexilate, the prodrug of dabigatran, but not dabigatran itself, is a P-glycoprotein substrate.
¶ Kidney and liver disease usually reduce drug clearance and thus increase drug half-lives.
** For example, 100% increase indicates that concentrations were double that of the reference healthy group.
†† See Australian Medicines Handbook interaction tables for more examples of drugs that inhibit or induce metabolic or transport pathways.