4341
To determine if routine risperidone treatment is associated with a unique degree of D2 receptor occupancy and pattern of clinical effects , we used [ 123I ] IBZM SPECT to determine D2 occupancy in subjects treated with routine clinical doses of risperidone ( n = 12 ) or haloperidol ( n = 7 ) .
 risperidone, risperidone, haloperidol
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 risperidone, risperidone, haloperidol