Step I phenoxybenzamine

[Northerncardinal]

Is phenoxybenzamine a noncompetitive alpha rec blocker or irreversible competitive antagonist??

(First aid confusion)

 

[W19]

A lot of books use these terms as synonymous... and they are the same for 'all practical purposes.'

 

[Jabbed]

Is phenoxybenzamine a noncompetitive alpha rec blocker or irreversible competitive antagonist??

(First aid confusion)

I've never heard of it described as a non-competitive alpha blocker (implies allosteric activity, which is definitely not true). It's an irreversible competitive antagonist, but functionally this is a distinction without a difference, as Km and maximal effect are equivalent when comparing irreversible competitive antagonists vs noncompetitive antagonists (Km is normal, maximal effect ↓).