This document discusses different types of combined drug effects, including reversible and irreversible effects as well as competitive and irreversible antagonism. Irreversible antagonism occurs when an antagonist binds irreversibly to the same receptor as the agonist through covalent bonds, meaning the effects of the antagonist cannot be overcome even with increased agonist concentration and the dose-response curve is shifted far to the right with minimal response. An example given is phenoxybenzamine antagonizing adrenaline.

1. COMBINED
EFFECTS OF DRUGS
ANKIT KUMAR (19)
PARA 15

9. EQUILIBRIUM NON EQUILIBRIUM
(REVERSIBLE) (IRREVERSIBLE)

11. COMPETITIVE IRREVERSIBLE ANTAGONISM
 Antagonist bind to same receptor in an
irreversible manner by covalent bonds.
 Effects of antagonist cannot be overcome even by
increasing the conc. of agonist.
 DRC shifted to right with minimal response.
 Eg- phenoxybenzamine – adrenaline.