Introduction
Inter-individual variability in pharmacological responses to medications
poses a significant burden on the capacity of healthcare systems
worldwide1. The modern concept of “personalized
medicine” aims at its core to facilitate selecting the right drug for
the right patient at the right dose with the minimum of adverse drug
reactions (ADR)2. ADRs are a serious cause of
hospitalizations and deaths in the United States3.The
percentage of patients who respond positively to their medications
ranges from 25-60%4. Almost 40% of patients suffer
from a treatment failure, in the form of negative therapeutic effects
and negligible desired benefits, necessitating switching from one
medication to another5.
Non-genetic factors, such as age, weight, gender, co-morbid disease
states, and drug-drug interactions, are well-documented to contribute to
such variability in clinical responses to drugs6.
However, genetic variation among individuals remains a principal cause
of the heterogeneity of drug responses in practice7.
Hence, pharmacogenomics (PG), the integrated analysis of the role of
genomics on responses to drugs8, is a promising new
approach that targets tailoring therapeutic regimens based on a person’s
genetic makeup9, thus improving the efficacy and
safety of drug prescriptions10, avoiding
ADRs11, and enhancing patient health
outcomes12. Most importantly, PG has an immense
potential for improving cost-effectiveness of
pharmacotherapy13 .
To date, more than 100 medicines have been included in the Food and Drug
Administration (FDA) repository of drugs labeled for PG analysis prior
to administration14, particularly those with a narrow
therapeutic index and a fatal toxic potential15, such
as antineoplastic16,
anticonvulsant17, and anticoagulant
drugs18. However, there remains a slow uptake of PG
applications in mainstream clinical care19, and many
of the FDA-recommended PG tests are unfortunately not in routine
use20. Although criteria for proper clinical
actionability of a novel test fundamentally apply to the available PG
tests21, including analytic
validity22, clinical validity23, and
clinical utility24, the alarming limited knowledge and
awareness of PG concepts among healthcare providers seem to critically
hinder its application25.
The responsibility of healthcare providers in improving the overall
quality of clinical care has incentivized recent efforts to integrate PG
testing in clinical practice26. Pharmacists and
physicians alike are nowadays aware of the need to adjust their clinical
roles to become more patient-oriented towards enhancing implementation
of personalized pharmacotherapy services27. However,
limited resources and poor understanding of PG persist to be a problem
in developing countries like Jordan28. Furthermore,
there are currently no comprehensive studies exploring correlates of PG
practice among the whole stratum of medical students, interns,
residents, and specialists, from all fields of medical practice in
Jordan. Thus, this study aimed to assess the knowledge, attitude, future
expectations, and practice of medical students and clinicians in
hospitals in Northern Jordan regarding PG testing, in addition to
determining their perceived barriers to its application.