Why do drugs work differently from person to person?
Many factors shape how our bodies process medications. Genetics is one piece of that picture, but age, diet, and other medications matter too. That’s why two people can take the same dose of the same medication and have very different results. Even identical twins can respond differently. The goal is to understand those variations well enough to prescribe the right drug at the right dose for each patient.
What is pharmacogenetics?
It’s the study of specific genes — primarily those that govern how the liver breaks down and moves drugs through the body. Certain gene variants can change how much of a medication reaches its target and how a person responds to it. Prescribing has long been based on averages from clinical trials, which works for many people but not everyone. Pharmacogenetics moves us toward a more individualized approach.
Can you give an example of how genetics change a drug’s effectiveness?
My favorite example is statins. They help lower cholesterol and prevent heart attacks, but they can cause severe muscle pain in people who have a genetic variant that makes it harder for their bodies to clear the medication, so higher levels stay in their bloodstream and leak into their muscle tissue.
How does pharmacogenetic testing work?
Patients at UCSF can have a panel of genes tested, often as part of their routine care, and the results stay in their medical record for future use. Clinicians can then use that information to guide drug and dosage decisions, reducing costly and potentially serious complications, hospitalizations, or ineffective treatments.
How do you ensure equitable access to testing?
One lesson we’ve learned repeatedly is that when new medical advances are introduced, they often reach some people sooner than others. At UCSF, we’re tracking who gets pharmacogenetic testing and whose medications or dosages change as a result — across race, ethnicity, income, and insurance cohorts — to ensure no group is left out.
Akinyemi Oni-Orisan, a professor of clinical pharmacy, leads an award-winning research lab focused on pharmacogenomics. He joined the faculty in 2017 after completing his postdoctoral training at UCSF.
