4177
Prolonged infusion of dexmedetomidine , an alpha ( 2 ) - adrenoreceptor agonist anesthetic used in the intensive care unit , produces a withdrawal syndrome of sympathetic over - activity , characterized by tachycardia , hypertension and agitation , but there is no recommended standard treatment for this syndrome .
 dexmedetomidine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 dexmedetomidine