Explained Personalized Medicines and Pharmacogeneticss with examples.

1. PERSONALISED
MEDICINES
SUBMITTED BY-VASUNDHRA KAKKAR
M.PHARM(PHARMACEUTICS)
SEMESTER-1

2. PERSONALIZED MEDICINES
• All patients do not respond to the same medicine in the same way.
• Some patients may experience adverse drug reactions that do not occur in
other patients taking the same drug at the same dose.
• A drug may also display varied efficacy in different patients.
• In the past, the differences in the risk-benefit ratio between patients taking
the same drug was attributed to non-genetic factors such as age, gender,
nutritional state, general medical condition (e.g. hepatic and renal dys-
function), lifestyle (diet, alcohol abuse, smoking), concomitant therapy or
the presence of comorbidity.
• Today, in addition to these factors the differences in patient genetic make-
up have been recognized to play an important role in the individual response
to drugs.

4. • Personalized medicine also called individualized or precision medicine is a
medicinal model that uses patient’s genetic profile to choose the proper
medication, therapy and dose in regards to the prevention, diagnosis and
treatment of the disease.
• Personalized medicine introduces the ability to use molecular markers that
signal disease risk or presence before clinical signs and symptoms appear.
• It offers the opportunity to focus on prevention and early intervention rather
than on reaction at advanced stages of disease.
• There are more than 15,000 tests for more than 2,800 genes.
• For example 1, women with certain BRCA1 or BRCA2 gene variations
have up to an 85 percent lifetime chance of developing breast cancer,
compared with a 13 percent chance among the general female population.
These women also have up to a 60 percent chance of developing ovarian
cancer, compared with a 1.7 percent chance among the general female
population. The BRCA1 and BRCA2 genetic test can guide preventive
measures, such as prophylactic surgery, and chemoprevention.

5. • Example 2- Some people are fast metabolizers, and hence they utilize
the drug quickly. Others are slow metabolizers with difficulties in
degrading down some drugs, leading to high risk of intoxication and
ADRs. Several tests are available to detect variations in CYP450
genes.
• Example 3- Azathioprine (AZA) is frequently used in treatment of
Crohn’s disease. Absence or low levels of thiopurine methyl
transferase (TPMT), an enzyme that is required to metabolize
azathioprine could lead to dose dependent side effects or even toxic
reactions. It is now required to check the TPMT level and genotype
before starting these medicines.

6. BENEFITS OF PERSONALISED
TREATMENT
• Direct the selection of optimal therapy and reduce trial-and-error
prescribing
• Help avoid adverse drug reactions
• Increase patient adherence to treatment
• Improve quality of life
• Help control the overall cost of health care

7. PHARMACOGENETICS
• Pharmacogenetics involves the study of single gene mutations and
their effect on drug response.
• Polymorphic variation in the genes that encode the functions of
transporters, metabolizing enzymes, receptors, and other proteins can
result in individual differences in the dose-plasma concentration
response relationships for many important therapeutic agents.
• the term Pharmacogenetics is used to refer to the study of inter-
individual variations in the DNA sequence that are related to drug
response and efficacy.
• Measuring the DNA differences can thus predict the variation in
response to the medicine.

9. • An advantage to using genetic testing as opposed to other types of
laboratory testing, such as measuring the concentration of the drug in
the blood during treatment, is that genetic tests can predict the
response to treatment before the treatment is started.
• In the past, systematic research into the basis of adverse drug
reactions has been hampered by the fact that these events are rare and
individuals are difficult to trace and study while suffering a reaction.
The ability to conduct genetic research retrospectively, at the end of a
clinical trial or after a medicine has been launched, using stored
samples of DNA, gives researchers a powerful new tool to explore
how medicines work.

10. • Such research will result in tests for responses to drugs that clinicians can
use to identify patients with a greater chance of effective response and
reduced risk of adverse reactions.
• Genetic markers to select appropriate treatment have, of course, been used
for decades. Whenever a patient needs a blood transfusion, the ABO blood
types—classic genetic markers—are used to identify the best match of
blood.
• Tissue typing before transplantation and Rhesus factor testing are other
examples.
• Trastuzumab (Herceptin; Genentech) has recently been licensed for treating
some types of breast cancer. It is a humanized monoclonal antibody against
the HER2 receptor and has been licensed together with a specific test
(Herceptest) to identify the appropriate subgroup of patients who
overexpress the HER2 receptor in the tumour tissue. This is the direction
that pharmacogenetics is likely to take drug treatment.

12. • Pharmacogenetics in cardiovascular medicine - These include genetic
tests to predict the maintenance dose and risk of bleeding with
warfarin, the possibility of myopathy and myositis with simvastatin,
and the risk of recurrent thrombotic events with clopidogrel .
• The cost of a pharmacogenetic test can be as low as $100 using low-
cost nanotechnology.