This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
True statement about clonidine are all except ? 
Select and explain. 
A. Increases parasympathetic outflow, B. Decreases sympathetic outflow by blocking central alpha receptor, C. Used in hypeension, D. Prazosin is used to antagonize side effects of clonidine
D: Prazosin is used to antagonize side effects of clonidine
Answer: D: Prazosin is used to antagonize side effects of clonidine 
Explanation: Ans. is 'd' i.e., Prazosin is used to antagonize side effects of clonidine Clonidine is an a-2 agonist, while prazosin blocks the a-1 receptors. o Clonidine enhances vagal tone (parasympathetic outflow) which can cause bradycardia. o The major haemodynamic effects result from stimulation of a2a receptors present mainly postjunctionally in medulla --> decrease sympathetic outflow --> fall in BP and bradycardia. o Clonidine is used in hypeension.