Pharmaco-What? Introducing Personalized Medicine

Adverse drug reactions: A major health issue

Every year, over 106,000 people in the United States die from adverse reactions to correctly prescribed doses of drugs.

Another 2.2 million suffer serious, but not deadly, side effects.

Three high school students, Marti, Toni, and Brianna, sought treatment for depression. Their doctor prescribed nortriptyline (pronounced nor-TRIP-ti-leen), a common antidepressant medication, for each girl.

After taking the medication for a month, Marti felt much better. She had few episodes of depression and no adverse reactions to the drug.

Toni's depression also had subsided. However, she could not sleep and often felt nauseated and anxious.

The medication didn't do much for Brianna: she felt neither better nor worse and had no adverse reactions to the drug.

Did all of the girls respond to the drug in the same way? No. In fact, their varied responses fit the typical pattern seen in all patients who take nortriptyline.

Not all patients are created equal

Evaluates how an individual's genetic makeup corresponds to the response to a particular medication.

People vary in their responses to any prescribed medication, both with respect to how well it works (its efficacy) and adverse reactions to it (side effects). Why would one girl benefit from the antidepressant drug, while another suffers severe side effects?

People also vary in their risk of getting certain diseases. Consider, for example, two 15-year-old boys who are the same height and weight, with similar diet and exercise habits. Why might one get diabetes while the other does not?

Combines pharmacogenetics with genomic studies. Uses large groups of patients to evaluate how candidate drugs interact with a range of genes and their protein products.

For both of these questions, one answer lies in our genes. The Human Genome Project has shown us that we are all 99.9 percent similar in our DNA. The variations within that remaining 0.1 percent, however, may correlate with different responses to medicines and extent of disease risk.

Is personalized medicine in our genes?

Researchers think so. Scientists, physicians and the pharmaceutical industry are actively developing ways to customize medical treatments to suit our unique genetic signatures. The study of how genetic variations interface with drug response and disease risk takes the form of two disciplines:

Pharmacogenetics (pronounced FARM-uh-co-je-NEH-tix) first emerged around the 1950s, when scientists began to notice that different responses to drugs ran in families and ethnic groups. This discipline aims to figure out how people's genetic variations correlate with their responses to a specific medication. The ultimate goal of pharmacogenetics is to tailor medical treatments specifically to the individual, increasing effectiveness while reducing adverse side effects.

Increase the efficiency of the drug development process and develop products that will benefit the largest population.

Pharmacogenomics (pronounced FARM-uh-co-je-NO-mix) evolved from pharmacogenetics in the 1990s, spurred by the success of the Human Genome Project. This discipline combines pharmacogenetics with the power of genomics, enabling researchers to study how different drugs interact with multiple genes and the biological molecules they encode. The ultimate goal of pharmacogenomics is to improve the overall process of drug development.

How might we benefit?

Through these studies, researchers aim to achieve the following medical advances:

Pharmacogenetics

Tests that predict patient drug response, match drugs with the patient and assess disease risk.
  • New, more accurate diagnostic tests that predict a patient's response to specific drugs based on his or her genetic profile.
  • Personalized drug therapies that match a patient with effective and safe medications based on information from diagnostic tests.
  • Personalized disease prevention strategies developed using genetic tests that estimate a patient's risk of getting a particular disease, combined with personalized drug therapies.

Pharmacogenomics

Reduce the time and money it takes to design superior medications that effectively treat specific patient populations.
  • Design of new, better medications through processes that reduce the overall cost and time for new drug development.

These two disciplines still have far to go, and the science is complex. Yet they have great potential to revolutionize drug development and therapy.

In this module, you will:

  • Explore several approaches to pharmacogenetics and pharmacogenomics
  • Try some of the methods used in these sciences
  • Learn about drug development and therapy
  • Learn the potential benefits of pharmacogenetics and pharmacogenomics
  • Consider the challenges and issues that face these two sciences
NCRR/SEPA

Supported by a Science Education Partnership Award (SEPA) [No. 1 R25 RR16291-01] from the National Center for Research Resources, a component of the National Institutes of Health, Department of Health and Human Services. The contents provided here are solely the responsibility of the authors and do not necessarily represent the official views of NCRR or NIH.