1645
RESULTS : Median maximum serum levetiracetam concentration was 25 . 5 microg / mL , median minimum serum levetiracetam concentration was 8 . 3 microg / mL , and median elimination half - life was 2 . 9 hours .
 Chemical: levetiracetam; Chemical: levetiracetam
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: levetiracetam; Chemical: levetiracetam