Harvard Medical School Prof. David Jones on personalized medicine, patients’ lifestyle, and genetic factors of treatment
Why can the same amount of drug have different effects on various people? When is it important to know the exact dose required for the patient? Professor of the Culture of Medicine at Harvard Medical School David Jones speaks on how biology helps doctors to prescribe treatment.
There was a series of researchers doing work in the late 1940s and early 1950s. What they were doing is that they pay close attention to how patients were responding to medicines. They would identify patients who had unusual reactions to these drugs and then they will look at family members of those patients to see if other people in the family also have this kind of peculiar reaction to drugs. And by doing this, doctors were able to identify series of families who had very unusual reactions to drugs and some of these things were quite dangerous.
This kind of medicine, this kind of personalized pharmacogenomic medicine is an excellent idea. And it certainly has the potential to transform medical practice. Two questions come up. One is how likely is it that it will transform medical practice? A second question is what are the opportunity costs of this kind of investment in pharmacogenomics as opposed to other things that researchers and doctors or patients can be doing to optimize the outcomes of medical treatment? Now, the answers here are complicated. If you talk to different people you get different answers. But one thing is clear: that for most drugs you probably don’t need to rely on pharmacogenomic testing.
Doctors and patients have long known that to be faithful in the daily ingestion of pills is really really difficult to do. Now in United States at least estimates are not compliant, so about 50%. So if give a patient a prescription the odds are they’ll take half of those pills. That is a huge effect on a level of the drug the patient’s body will actually get. And that effect is much much larger than many of the effect size reported for pharmacogenomics. So if you’re a doctor and you want to get the best possible outcomes for your patients should you do a thousand dollars gene test to find out their drug metabolizing variance? Or should you figure out what’s preventing them from taking their pill every day?