Adrenergic antagonists

[PHW2:Chp14]

Classification

Alpha antagonists

• Non-selective alpha antagonists
  * Phentolamine
  * Phenoxybenzamine
• Selective alpha1 antagonists
  * Prazosin
• Selective alpha2 antagonists
  * Yohimbine

NB:

Phenoxybenzamine

[PHW2:p221]

Active metabolite which forms covalent bond to alpha receptors
--> Irreversible blockade

Used in preoperative management of phaeochromocytoma