3568
Because salicylates have been reported to augment the stimulatory effects of caffeine on the CNS , attention was focused on the possibility that the presence of acetaminophen ( 52 micrograms / mL ) reduced the CNS toxicity of caffeine .
 caffeine, acetaminophen, toxicity, caffeine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 caffeine, acetaminophen, toxicity, caffeine