what is non-competitive (or irreversible or insurmountalbe) antagonism? is it really irreversible?
in competing for receptors, the antagonist has the advatage - it has more affinity for the receptor, or changes the shape of the receptor so the agonist cannot fit into it anymore. the antagonist "wins". it is not really irreversible - it just takes a long time or a lot more of the agnoist drug to reverse.