48
Management
Table 13. OACs Pharmacokinetic Characteristics and Dosing
(cont'd)
Class VKA Direct Thrombin Inhibitor
Name Warfarin Dabigatran
Drug interaction
management based on
concomitant therapy of
p-glycoprotein/ CYP3A4
inducers (eg, carbamazepine,
phenytoin, rifampin, St.
John's wort)
Adjust dose based on
INR trends
Avoid use
Appropriate use based on
liver function (Child-Pugh
score)
†
Child-Pugh A (mild)
Not mentioned in the
labeling
No dose adjustment needed
Child-Pugh B (moderate) Use with caution
Child-Pugh C (severe) Avoid use
* e effect of food (high-fat, high-calorie meal) on bioavailability for 10- and 20-mg tablet
was evaluated in 24 subjects under fed and fasting conditions. Aer a single oral 20-mg
dose, area under the curve was increased by 39%, and Cmax was increased by 76% under
fed condition, but area under the curve and Cmax were similar between fasting and fed
conditions.
† Child-Pugh scoring : the severity of liver disease, primarily cirrhosis. Child-Pugh A (mild):
5 to 6 points; Child-Pugh B (moderate): 7 to 9 points; Child-Pugh C (severe): 10 to 15
points. e score is based on the 5 variables: encephalopathy (none=1 point, grade 1 and
2=2 points, grade 3 and 4=3 points); ascites (none=1 point, slight=2 points, moderate=3
points); total bilirubin (<2 mg/mL=1 point, 2-3 mg/mL=2 points, >3 mg/mL=3 points);
albumin (>3.5 mg/mL=1 point, 2.8-3.5 mg/mL=2 points, <2.8 mg/mL=3 points); INR
(<1.7=1 point, 1.7-2.2=2 points, >2.2=3 points).
Information obtained from manufacturer package inserts. Adapted with permission from
pgs. 28–31 of Kido K. Copyright 2021, American College of Clinical Pharmacy.
