Patients apparently eager for pharmacogenics-based prescribing
Bioethicists can ensure benefits are understood
EXECUTIVE SUMMARY
Pharmacogenics-based prescribing can determine whether individual patients will benefit from certain drugs, and there is broad public support for this. Some ethical considerations:
- Whether there is an evidence base to show that the testing is really going to make a difference;
- Whether all patients will have the opportunity to benefit from the testing;
- How to respond to people wanting to be tested when a good evidence base is lacking.
Tests are now available to determine whether individual patients will benefit from certain drugs, with the goals of physicians no longer needing to rely on "trial and error" prescribing.
"This seems to be something that patients understand and gravitate toward more than just about anything. They like the idea of having drugs that work that don't make them sick," says Ellen Wright Clayton, MD, JD, Craig-Weaver Professor of Pediatrics and professor of law at Vanderbilt University's Center for Biomedical Ethics and Society in Nashville, TN.
Vanderbilt's Pharmocogenic Resource for Enhanced Decisions in Care and Treatment (PREDICT) program, launched in 2010, has genotyped more than 14,000 Vanderbilt patients for 184 different genetic variations that affect the body's response to various drugs.
More than 12,000 of the patients (88%) have genetic variations that increase their risk of adverse effects from one or more of the five drugs currently included in the electronic health record. Here are some ethical considerations with pharmacogenomics:
- Whether there is an evidence base to show that the testing is really going to make a difference.
"This is an ongoing problem in medicine as we introduce new technologies, and is really no different here," says Clayton. "What is a little different is that many of the enzymes that are involved in drug metabolism have a variety of substrates, and may affect other biological pathways."
Some have effects that are not just limited to drug metabolism. "So one challenge is defining what are you going to tell patients about other implications of their variants," says Clayton.
This concern is not unique to pharmacogenomics, however. "We run into this all the time in medicine," says Clayton. "But it is certainly something that needs to be considered."
- Whether all patients will have the opportunity to benefit from the testing.
"Justice is obviously a pervasive issue in our health care system even now," says Clayton. "I think that what we will see is that as the testing proves its worth, as it is likely to in many instances, it will become a routine part of medical practice."
Third party payers will recognize the benefits of avoiding adverse events and ensuring that people get effective drugs, she predicts, because "nobody benefits if people get drugs that don't work or make them sick."
Broad public support
During qualitative interviews conducted with Vanderbilt's patients over the past few years, the typical response has been, "What could be bad about this?"
"People feel differently about this than they do about predisposition testing," says Clayton. "What makes this more salient to patients is that the information is used to make a decision that is pertinent to that point in time."
Vanderbilt offers people at high risk for needing any of the drugs the opportunity to be tested in advance, so the results are available at the time they need it.
"Most people do not seem to worry if they have genetic information sitting in their medical record until such time as they need it," says Clayton. "They are not going to be fretting about it the same way they would a predisposition to cancer or a neurological disorder."
Technology is evolving
"As these tests prove their value — and some will and some won't — then they will become a part of what clinicians are prepared to offer patients," predicts Clayton. As the value of the testing becomes clear, with proof that outcomes are improved, she says, it is only a matter of time before it becomes incorporated into clinical care.
"The more difficult ethical issue is people wanting to be tested for things when we don't have a good evidence base to say that it's warranted," says Clayton.
Bioethicists can contribute to the process by asking these two questions, says Clayton:
- Do we have the evidence to ensure that doing these tests provides value to patients?
- If there are pleotropic effects, how can these be communicated to patients in a way that is going to be meaningful to them?
"People who work in ethics are certainly devoted to making sure patients make as informed decisions as they can," says Clayton. "By asking direct questions, they can ensure that the new tests are beneficial and that patients know what they are getting into."
- Ellen Wright Clayton, MD, JD, Craig-Weaver Professor of Pediatrics, Professor of Law, Center for Biomedical Ethics and Society, Vanderbilt University, Nashville, TN. Phone: (615) 322-1186. E-mail: [email protected].
