4499
For the subsequent 6 - week double - blind crossover phase ( phase B ) , patients taking standard - or low - dose haloperidol were switched to placebo , and patients taking placebo were randomly assigned to standard - or low - dose haloperidol .
 haloperidol, haloperidol
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 haloperidol, haloperidol