New UCSF Test Helps Find the Right Medication for You Using Your DNA

Starting today, doctors at UCSF may be able to prescribe medications with a lot more accuracy.

The hospital says it’s the first in California to test a patient’s genes to see how they respond to drugs using a process called pharmacogenetics.

Traditionally, doctors have relied on trial-and-error to determine how a patient responds to medication, offering a prescription usually based on gender, weight and age.

But now, using a blood test, UCSF can examine with precision how variants in a person’s DNA could influence how they respond to particular drugs.

The new program will alert physicians “at that moment when they’re prescribing that this is going on with the genetics and this is what we recommend,” said Dr. Bani Tamraz, professor of clinical pharmacy at UCSF, who co-leads the UCSF pharmacogenetics program. “It’s all very nicely integrated into the system.”

Pharmacogenetics is a game changer for patients like 47-year-old Christine Von Raesfeld, who looks exceedingly happy and healthy, with a warm smile and curly black hair. Raesfeld has been diagnosed with many conditions including lupus, thrombotic thrombocytopenic purpura and autoimmune autonomic ganglionopathy and experiences a long list of associated symptoms: chronic pain, fatigue, insomnia, brain fog and joint tenderness.

“I’ve got over 40 diagnoses in my charts at this point,” she said.

The Stanford medical library has been a refuge for Von Raesfeld. “I would spend hours as a kid just pouring over medical books, just trying to find information on me,” she recalled.

For a while, doctors treating Von Raesfeld’s symptoms with drugs only made things worse, especially with three medications she took to treat lupus in her late 20s that she says resulted in three joint replacements, toxic encephalopathy and night-vision loss.

“I’m half Asian,” she said. “So, a lot of those drugs are tested on white populations. And so I think some of my genetics played a role in causing these adverse reactions.”

Finally, she took a genetic test that showed many of her prescriptions were either the wrong dose or the wrong drug. For example, her psychiatric medications were too high of a dosage, and she doesn’t respond at all to opioids.

The test also explained why the steroids she took in her 20s failed miserably: She metabolized them slowly.

“It was working,” she explained, “but they kept feeding me the drug and it was just sitting in my system. They were then doubling and tripling the dose.”

That was until, she says, she gained 70 pounds and her skin began ripping and bleeding.

With pharmacogenetics, doctors can see exactly why a person is experiencing a side effect, Tamraz of UCSF explained.

“You can see, ‘Oh, well, no wonder,’” he said. “Because they have this particular gene that is causing them to accumulate more of the drug in their system. They’re not clearing it. And so we either pick a different drug or we need to adjust the dose.”

Tamraz hopes the new program will reduce negative side effects.

UCSF plans to bill each patient’s insurance, but not all insurers cover the test. Companies argue that more evidence is needed to demonstrate it improves care and lowers cost.

Also, pharmacogenetics currently is offered only at a select number of U.S. hospitals with large academic institutions, like the Mayo Clinic, where Dr. Richard Weinshiloboum is a professor of medicine and pharmacology.

“There continues to be a controversy about how valuable this is, but the one thing I can say for sure is that increasingly this is becoming a standard part of drug therapy for specific drugs that could have a serious adverse reaction,” he said.

For example, a chemotherapy treatment for leukemia can be deadly for certain children. Estimates vary but studies suggest medications accidentally kill more than 100,000 people a year across the country.

“These are powerful drugs,” Weinshiloboum said. “They can do great good, but occasionally they can do great harm. Those things are sometimes due to differences in your genetics.”

Von Raesfeld hopes pharmacogenetics is more widely available soon.

“My whole life has been turned upside down from damage from medications,” she said. “And so, the only thing I can think of is to get testing like this out to the public so that no one else has to deal with these things.”

Today Von Raesfeld is taking four medications — down from 40.

It’s the first time in her life she says her treatment is helping rather than hurting her.