This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adrenergic System, Subject name: Pharmacology
Dexmeditomedine is a: 
Select and explain. 
A. Centrally acting alpha-2 agonist, B. Centrally acting alpha-2 antagonist, C. Peripherally acting alpha-2 agonist, D. Peripherally acting alpha-2 antagonist
A: Centrally acting alpha-2 agonist
Answer: A: Centrally acting alpha-2 agonist 
Explanation: Ans. a. Centrally acting alpha-2 agonist (Ref: KDT 7/e p384; Katzung 12/e p445)Dexmedetomidine is an alpha-2 agonist with strong sedative properties.'Dexmedetomidine is an alpha-2 agonist with strong sedative properties. It has a half-life of 2-3 hours and is metabolized in the liver and excreted, mainly as metabolites, in the urine. - Katzung 12/e p445'Dexmedetomidine is a centrally active selective alpha-2a agonist that has been introduced for sedating critically ill/ventilated patients in intensive care units. It is also being used as an adjunct to anaesthesia Analgesia and sedation are produced with little respiratory depression. Sympathetic response to stress and noxious stimulus is blunted. It is administered by i.v. infusion. Side effects are similar to those with clonidine (hypotension, bradycardia and dry mouth). It has been recently approved for use in India as well. KDT 7/e p384