Drug idiosyncrasy and pharmacogenetics

Drug Idiosyncrasy and
Pharmacogenetics

Idiosyncrasy(Definition):
 Drug idiosyncrasy is an abnormal
individual response to a drug
causing an effect quite different
from that expected. Idiosyncracy
is inherent in the person
concerned and is usually due to
a genetic anomaly. It may take
the form of hypersensitivity so
that the normal effect is
produced by a dose which is a
small fraction of the standard
dose. In pharmacology,
idiosyncrasy refers to an
idiosyncratic reaction

Idiosyncratic drug reaction:
 Idiosyncratic drug
reactions, also known as
type B reactions, are drug
reactions that occur rarely
and unpredictably amongst
the population. This is not
to be mistaken with
idiopathic, which implies
that the cause is not
known

Mechanism of idiosyncratic reaction:
Foreign molecule binds to antibody and cellular damage is happened
Drugs do not show immunological response as they are too small to induce immune response
Some drugs bioactivated into a toxic compound that will in turn bind to proteins
Cellular damage can come either from drug/drug metabolite or from injury or infection
This creates response and then toxicity

“
”
Fig:Adverse drug reaction

Causes of Idiosyncrasy:
Drug idiosyncrasy depends
on
Genetic type of
individual person
Dose of Individual drug

Idiosyncratic Behavior:
 Any behavior deemed by the
''average'' level norms and
expectations of the world
culture as odd, different,
individualistic, idiosyncratic.
 Basically, anyone on either
end of the entire spectrum
of human intelligence usage
levels, from ''crazies'', to
''geniuses'', and all the way
back around to the
beginning.

Examples:
 An simple example of
idiosyncrasy is someone
being allergic to air.
Many drugs precipitate
idiosyncratic toxicities. As
an example, antipsychotic
drugs such as
chlorpromazine and
clozapine cause
infrequent reactions such
as rhabdomyolysis
(breakdown of striated
muscle) and liver toxicity.

 Pharmacogenetics is a noun
which refers to the study of
how genetic differences
among individuals cause
varied responses to a drug .
Mainly it is the branch of
pharmacology concerned
with the effect of genetic
factors on reactions to
drugs.

How does genetic variation affect drug effect?

Pharmacogenetics Vs Pharmacogenomics:

Pharmacogenetics tests:
 Various types of pharmacogenetics tests are
1.HLA gene test
a)ABACAVIR & HLAB*5701
b)ANTICONVULSANTS & HLAB*1502
c)CLOZAPINE & HLA-DQ 1*02101
2.Drug metabolism related gene test
a)THIOPURINE & TPMT
b)5-FLUOROURACIL (5-FU) & DPYD
c)TAMOXIFEN & CYP2D6
d)IRINOTECAN & UGT1A1*28

 3.Drug target related
gene test
a)Trastuzumab & HER 2
b) DASATINIB , IMATINIB
& BCR-ABL 1
4.Combined(metabolism
and target) gene test
a)WARFERIN & CYP2C9
+ VKORC 1 GENOTYPING

Importance of Pharmacogenetics:
 Pharmacogenetics deals with the differences in effect of
drugs caused by genetic variation. ... Genetic variation in
metabolism may result in high concentrations of drugs and
an increased risk of adverse effects in slow metabolizers,
which is important when using for example
antidepressants or chemotherapy.

Ineffectiveness of drugs for genetic criteria:

THANK YOU
Presented By:
Nosaibaton Morsheda
Tohfa

Drug idiosyncrasy and pharmacogenetics

More Related Content

What's hot

Similar to Drug idiosyncrasy and pharmacogenetics

Recently uploaded

Drug idiosyncrasy and pharmacogenetics