Week 10 Flashcards
Polymorphism –
Drug interaction
Results in an exaggerated effect or
minimal effect on the substrate
Inhibitor: An enzyme inhibitor is a
molecule, which binds to enzymes
and decreases their activity.
Inducer: An enzyme inducer is a type
of drug that increases the metabolic
activity of an enzyme either by
binding to the enzyme and activating
it, or by increasing the expression of
the gene coding for the enzyme
Polymorphism –
Drug interaction extensive metabolizers (inhibitors)
Extensive Metabolizers (EM) - Inhibitors
Extensive metabolizer —– level of
substrate drug is normally low due to
rapid metabolism by the enzyme.
An inhibitor to the enzyme will inhibit the
extensive metabolism and cause
significant elevations in the substrate
drug.
Polymorphism –
poor metabolizers - inhibitors
In a poor metabolizer, the level of substrate drug
remains high because the metabolism of the
substrate is much less than normal.
When an inhibitor is added, the additional
inhibition of metabolism is not much greater than is
already occurring in the PM.
The effect of inhibitor is less in a PM than in
normal metabolizers.
Polymorphism –
Drug interaction extensive metabolizers (Inducers)
Level of substrate drug is lower than in a normal
metabolizer due to rapid metabolism.
The addition of an inducer does not cause a
greater difference in the level of substrate because
the metabolism is already increased greatly.
The drug interaction might not occur.
Polymorphism –
poor metabolizers - Inducers
Level of substrate drug is higher than expected in
normal metabolizer because of the lower
metabolism of substrate.
The addition of inducer will cause a significant
increase in the metabolism of the substrate -much
lower level of substrate than expected in a normal
metabolizer.
Drug interaction may occur to a greater extent.
Drug interaction may result in substrate levels like
those of normal metabolizers.
