21567
Varenicline and cytisine did not fully substitute for nicotine and , as compared with nicotine , their ED50 values varied less systematically as a function of nicotine training dose .
 Chemical: Varenicline; Chemical: cytisine; Chemical: nicotine; Chemical: nicotine; 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: cytisine; Chemical: nicotine; Chemical: nicotine; Chemical: nicotine