4448
Both plasma pethidine and norpethidine were elevated in the range associated with clinical manifestations of central nervous system excitation .
 Chemical: pethidine; Chemical: norpethidine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
 Entities: pethidine, norpethidine 
Answer:
 Chemical: pethidine; Chemical: norpethidine