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Warfarin, also known under the brand names of Coumadin, Jantoven, Marevan and Waran, is an oral anticoagulant used worldwide for the treatment and prevention of thromboembolic disease. However, warfarin therapy can be difficult to manage because there is a wide variability in patient response and the drug has a narrow therapeutic index. Taking too small a dose can lead to a blood clot while too much can cause life-threatening bleeding.

Single nucleotide polymorphisms (SNPs) in the genes CYP2C9, which influences metabolism, and VKORC1, which influences pharmacodynamic response (meaning the biochemical and physiological effects of the drug on the body), are strongly associated with warfarin responsiveness [1]. According to an article in Wired Science last year [2]:

Doctors in the field say that traditional measurements such as size and age account for just 15% to 20% of the variability in responses to warfarin. Adding the genetic factors can raise that figure to 50% or higher, say advocates of genetic testing.

Indeed, experts estimate that integrating genetic testing into routine warfarin therapy could avoid 85,000 serious bleeding events and 17,000 strokes annually [3]. Integrated genetic testing in warfarin therapy is estimated to reduce healthcare spending by $1.1 billion U.S. annually.

Helix Health, the first U.S. stand-alone genomic medicine practice, is hosting a 90-minute CliniCast today (Monday, June 30, 2008) 
from 1:00 — 2:30 PM EDT to examine how genomic medicine improves the accuracy of warfarin dosing. The CliniCast will feature Dr. Steven Murphy (the GeneSherpa) and a panel of medical, scientific and legal experts.

The group will discuss a number of topics:

• Why genetic testing is a necessary feature in anticoagulant therapy.
• What potential risks exist in “Trial and Error” dosing?
• Will insurance cover this genetic testing?
• What are potential tort issues in predictive genetic testing and medical uses of genetic tests associated with anticoagulant therapy?
• Why aren’t physicians utilizing FDA approved testing and dosage guidance?

To register for the free webcast, point your browser here: http://event.netbriefings.com/event/helixhealth/Live/warfarin/register.html

A podcast of the CliniCast will be available on Helix Health following the session. For more information, contact info@helixhealth.org or visit Helix Health.

Additional resources can be found in the Personalized Medicine category of the Highlight HEALTH Web Directory.

There are a number of genetic tests currently available that can help predict response to certain medications. Clinical studies are currently being conducted to understand the connection between genotype and warfarin dose for the delivery of optimized anticoagulant therapy. Given the widespread use of warfarin, I anticipate an interesting discussion on the Helix Health CliniCast and encourage everyone to register and attend.

References

1. Cooper et al. A genome-wide scan for common genetic variants with a large influence on warfarin maintenance dose. Blood. 2008 Jun 5. [Epub ahead of print]
   View abstract
2. Genomic Medicine Hits Mainstream Milestone. Wired Science. 2007 Aug 17.
3. Health Care Savings from Personalizing Medicine Using Genetic Testing: The Case of Warfarin. Andrew McWilliam, Randall Lutter, Clark Nardinelli. Working Paper 06-23. 2006 Nov.

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The Human Genome Project has heralded a new era in our understanding of the molecular basis of disease. Genome-based medicine or personalized medicine is believed to be the future of healthcare. Indeed, genomic medicine is poised to improve disease diagnosis, therapy and prevention.

Although genomics is related to genetics, there is a difference between the two terms. Genetics is the study of single genes and their effects. In contrast, genomics is the study of all the genes in the genome and the interactions among them and their environment. Genetics uses the information from one or two genes to describe a disease state, whereas genomics examines all genetic information to determine biological markers predisposing a person to disease. Genomics is especially relevant for complex or multifactoral disorders such as cancer, Parkinson’s disease, heart disease and diabetes, which are due to the interaction of multiple genes and environmental factors [1].

photo credit: pinkbelt

With the sequencing of the human genome and the development of genomic technologies, medicine is entering a transition period whereby specific genetic knowledge will be critical for the delivery of effective healthcare. Many questions surround the state of this transition. A recent systematic review published in the Journal of the American Medical Association attempted to synthesize peer-reviewed published information on the delivery of genomic medicine for common adult-onset chronic diseases such as cancer, diabetes and coronary heart disease [2]. While advances in genetics and genomics have been extensive, the review found a large disparity between what is known and what is needed by healthcare professionals [2]:

Our systematic review reveals a large gap between what knowledge is available and what health systems still need to know about the outcomes, consumer needs, organization of health services, and barriers, to ensure appropriate and effective clinical integration of genomic information and technologies for common chronic disease.

Dr. Steve Murphy frequently discusses this disparity at Gene Sherpas: Personalized Medicine and You. Steve is also the founder of Helix Health, the country’s first stand-alone genomic medicine practice.

To educate and promote personalized medicine, Steve has announced that Helix Health will host at minimum monthly podcasts on a variety of topics.

The first event is a free 90-minute webcast titled “How Genomic Medicine is Changing the Management of Breast & Ovarian Cancer.” The webcast is scheduled for this Wednesday, May 21st, from 1:00 — 2:30 pm EDT [3].

The webcast will feature David Ewing Duncan, bestselling author of Masterminds: Genius, DNA and the Quest to Rewrite Life and Chief Correspondent and co-host of National Public Radio’s “Biotech Nation”, a panel of distinguished medical and legal professionals, and Jessica Queller, author of Pretty Is What Changes: Impossible Choices, The Breast Cancer Gene, and How I Defied My Destiny.

The group will discuss how the doctor-patient relationship is changing and what the potential liability is for physicians in this transition period for genomic medicine and breast & ovarian cancer.

• What should a doctor and patient do when a patient tests positive?
• What is the risk in taking a “wait and see” approach?
• Are there alternatives to radical surgery?
• What are potential tort issues in predictive genetic testing and medical uses of
  genetic tests?

To register for the free webcast, point your browser here: http://event.netbriefings.com/event/helixhealth/register.html

For more information, contact info@helixhealth.org or visit Helix Health.

Additional resources can be found in the Personalized Medicine category of the Highlight HEALTH Web Directory.

The Helix Health webcast should be very informative. I anticipate an interesting discussion on genetic testing, genomic medicine and breast & ovarian cancer, and encourage everyone to register and listen in this Wednesday, May 21st.

Resources

1. Guttmacher and Collins. Genomic medicine — a primer. N Engl J Med. 2002 Nov 7;347(19):1512-20.
   View abstract
2. Scheuner et al. Delivery of genomic medicine for common chronic adult diseases: a systematic review. JAMA. 2008 Mar 19;299(11):1320-34.
   View abstract
3. How Genomic Medicine Is Changing the Management of Breast & Ovarian Cancer. Helix Health Press Release. 2008 May 16.

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iGuard is one of the first web-based services that allows you to get free personalized safety alerts and updates about your medications. The company claims that [1]:

… patients can feel safer because they will be sent the drug safety information they need, when they need it.

After enrollment, patients who regularly take medications can choose to receive patient-specific updates regarding the safety of their medications. Participants in iGuard will receive these updates whenever new information is learned about their medicines, allowing them to make the most informed decisions about their healthcare.

In 2006, the Institute of Medicine released a report, “The Future of Drug Safety: Promoting and Protecting the Health of the Public”, which advised expansion of the Food and Drug Association’s (FDA) authority to require postmarketing surveillance of approved drugs [2]. The report found that the drug safety system in the U.S. is impaired by a number of factors, including:

• Serious resource constraints that weaken the quality and quantity of the science that is brought to bear on drug safety.
• An organizational culture in the Center for Drug Evaluation and Research (CDER) that is not optimally functional.
• Unclear and insufficient regulatory authorities particularly with respect to enforcement.
• FDA and the pharmaceutical industry do not consistently demonstrate accountability and transparency to the public by communicating safety concerns in a timely and effective fashion.

Most drug approvals are based on clinical trials involving a few hundred or a few thousand patients, but many uncommon side effects don’t emerge until a drug is being used by millions of people. iGuard automatically distributes information information received from the FDA and from drug manufacturers as alerts to patients. In addition, they have a clinical review team that evaluates other sources, including journals, academics and private researchers, which may also warrant an alert to patients. With iGuard, patients and physicians will have access to the most current information available associated with individual medications.

Drug safety is an important issue. Indeed, a study recently published in the Archives of Internal Medicine analyzing all serious adverse drug events and medication errors in the U.S. reported to the FDA from 1998-2005 found that there was a marked increase in reported deaths and serious injuries associated with drug therapy over the study period [3].

An online webcast is scheduled for this Thursday, October 4th at 2:00 PM EST. The webcast will be presented by Hugo Stephenson, M.D., B.Sc. and Judith Jones, M.D., Ph.D. and will provide information on what iGuard is and how it works. They will explain how simple it can now be for anyone and everyone to better assess the level of risks associated with the drugs they are taking or prescribing. Listeners will be able to ask any questions live via email and have them answered by Dr. Stephenson and Dr. Jones during the webcast.

I believe iGuard is a valuable initiative with great potential. It’s an important resource for e-Patients and one that can help you manage your own healthcare in partnership with your doctor. I encourage you to listen in this Thursday, October 4th and see if iGuard can help you.

UPDATE: The webcast is available for the next 3 months here.

References

1. The iGuard Vision. http://www.iguard.org/help/about/.
2. The Future of Drug Safety: Promoting and Protecting the Health of the Public. Institute of Medicine of the National Academies. 2006 Sep 22.
3. Moore et al. Serious adverse drug events reported to the food and drug administration, 1998-2005. Arch Intern Med. 2007 Sep 10;167(16):1752-9.
   View abstract

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