Textbook of Personalized Medicine - Second Edition [2015]

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before prescribing in order to determine which drug regimen best fi ts their genetic
makeup. Pharmacogenomic studies are rapidly elucidating the inherited nature of
these differences in drug disposition and effects, thereby enhancing drug discovery
and providing a stronger scientifi c basis for optimizing drug therapy on the basis of
each patient’s genetic constitution.

Pharmacogenomics vs Pharmacogenetics

Pharmacogenomics, a distinct discipline within genomics, carries on that tradition
by applying the large-scale systemic approaches of genomics to understand the
basic mechanisms and apply them to drug discovery and development.
Pharmacogenomics now seeks to examine the way drugs act on the cells as revealed
by the gene expression patterns and thus bridges the fi elds of medicinal chemistry
and genomics. Some of the drug response markers are examples of interplay
between pharmacogenomics and pharmacogenetics; both are playing an important
role in the development of personalized medicines. The two terms – pharmacoge-
netics and pharmacogenomics – are sometimes used synonymously but one must
recognize the differences between the two as shown in Table 5.2.

Table 5.2 Pharmacogenetic vs. pharmacogenomic studies

Feature Pharmacogenetics Pharmacogenomics
Focus of studies Patient variability Drug variability
Scope of studies Study of sequence variations in
genes suspected of affecting
drug response

Studies encompass the whole genome

Methods of study SNP, expression profi les and
biochemistry

Gene expression profi ling

Relation to drugs One drug and many genomes
(patients)

Many drugs and one genome

Examination of drug
effects

Study of one drug in vivo in

different patients with

inherited gene variants

Examination of differential effects of
several compounds on gene
expression in vivo or in vitro
Prediction of drug
effi cacy

Moderate High value

Prediction of drug
toxicity

High value Moderate

Application relevant to

Personalized Vaccines

medicine

Patient/disease-specifi c

healthcare

Drug discovery and development or

drug selection

© Jain PharmaBiotech

Pharmacogenomics vs Pharmacogenetics