2607
METHOD : Twenty cocaine - dependent participants were randomly assigned to receive modafinil , 400 mg ( N = 10 ) , or placebo ( N = 10 ) every morning at 7 : 30 a . m . for 16 days in an inpatient , double - blind randomized trial .
 cocaine, modafinil
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 cocaine, modafinil