from
The Collaborative International Dictionary of English v.0.48
mechanism of action \mech"an*ism of ac"tion\, n. (Medicine,
Biochemistry)
The mechanism[2] by which a pharmacologically active
substance produces an effect on a living organism or in a
biochemical system; as, the mechanism of action of
actinomycin involves its binding to DNA. The mechanism of
action is usually considered to include an identification of
the specific molecular targets to which a pharmacologically
active substance binds or whose biochemical action it
influences; a general recognition of the broad biochemical
pathways (such as DNA synthesis, protein synthesis,
cholesterol synthesis) which are inhibited or affected by a
substance is termed its {mode of action}.
[PJC]