21889
This was then followed by the continued administration of a weekly thyroxine bolus for a four - week period after which TSH and free T4 levels were recorded .
 Chemical: thyroxine
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: thyroxine