2016
The two metabolic phenotypes , extensive ( EM ) and poor metabolizers ( PM ) , show different stereoselective metabolism , resulting in apparently higher beta - 1 adrenoceptor antagonistic potency of racemic metoprolol in EMs .
 Chemical: metoprolol
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: metoprolol