Switching - Warfarin to Acenocoumarol48
The relationship between maintenance dosages of three vitamin K antagonists: Acenocoumarol, warfarin and phenprocoumon
van Leeuwen Y et al., Thromb Res. 2008;123(2):225-30.
In clinical situations (e.g. warfarin resistance, coumarin sensitivity), needing a switchover of therapy from one coumarin derivative to another, it is often difficult to arrive at a precise dose of the drug.
To develop a transition algorithm for the maintenance dosages of three frequently used coumarins: warfarin, phenprocoumon and acenocoumarol.
Fifty-eight patients switched from warfarin to phenprocoumon, 39 from acenocoumarol to phenprocoumon and 44 from acenocoumarol to warfarin. Each treatment was administered for 6 months.
Transition factors of maintenance doses for switch-over of coumarins
|Direction of switch||Transition factor||95% CI|
|Warfarin - phenprocoumon||0.41||0.39-0.43|
|Phenprocoumon - warfarin||2.36||2.24-2.48|
CI, confidence interval.
Dose conversion chart -Warfarin to Acenocoumarol48
|Warfarin dosage (mg)||Transition factor*||Acenocoumarol dosage (mg)|
*Transition factor-0.53 is taken as approx 0.5 for calculation of dosage