1984
Doses were flexibly titrated up to 0 . 6 mg / day for clonidine and 60 mg / day for methylphenidate ( both with divided dosing ) .
 clonidine, methylphenidate
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 clonidine, methylphenidate