21571
Varenicline did not antagonize the effects of nicotine , whereas cytisine produced a modest though significant antagonism of nicotine .
 Chemical: Varenicline; Chemical: nicotine; Chemical: cytisine; Chemical: nicotine
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: Varenicline; Chemical: nicotine; Chemical: cytisine; Chemical: nicotine