A<unk>  is a type of medication which inhibits postganglionic transmission, primariliy by acting as a nicotinic antagonist, for example hexamethonium, pentolinium, mecamylamine, trimetaphan and pempidine.<unk> s are used less frequently now than they were in the past, because more selective agents are now available. However, they are still used in some emergency situations, such as aortic dissection.
Ganglionic blocker
Alpha-adrenergic agonist
Beta-adrenergic agonist
Adrenergic agonist
Muscarinic agonist
Anticholinergic
Antihypertensive
Alpha blocker