29041
Alternative anticoagulants to warfarin ( dabigatran , rivaroxaban and apixaban ) are becoming available for the prevention of thromboembolic stroke in atrial fibrillation , but there is a lack of information on their comparative effectiveness .
 Chemical: warfarin; Chemical: dabigatran; Chemical: rivaroxaban; Chemical: apixaban
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: warfarin; Chemical: dabigatran; Chemical: rivaroxaban; Chemical: apixaban