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UCSF study finds no benefit to guidelines limiting blood pressure drugs for Black patients

Cathie Anderson
·3 min read

In an attempt to help Black patients better control their high blood pressure, eminent medical societies from around the world instituted race-based guidelines that have long limited the range of medications Blacks can access when diagnosed with the condition.

Their recommendations were based on clinical trials that have since come under scrutiny, but they were drilled into the heads of a generation of primary care physicians during medical school and continue to influence who gets access to different medications for hypertension, say researchers from the University of California, San Francisco, in a study published in the Journal of the American Board of Family Medicine.

Although this race-based approach to prescribing is widespread, the UCSF researchers said, it has no apparent benefit for patients. After analyzing two years worth of information from electronic medical records, the UCSF team discovered that almost half (46.4%) of the Black patients had uncontrolled hypertension, compared with 39% of the non-Black patients.

“Race-based guidelines distract clinicians from providing targeted interventions that address known social determinants of health and from addressing implicit biases that disproportionately and negatively impact Black patients,” said Dr. Hunter K. Holt, who did this research when he was a primary care research fellow in the UCSF Department of Family and Community Medicine. “Now is the time for more research to better understand whether the guidelines that were intended to rectify the racial health disparities may actually be further contributing to the divide.”

Holt and his team pulled data on 10,875 San Francisco Bay Area patients diagnosed with hypertension, 20.6% of whom were identified as Black. Doctors had put the patients on one- or two-drug regimens from these medications:

  • Lisinopril, benazepril or another angiotensin converting enzyme inhibitor (ACEI), which relax the blood vessels;

  • Losartan, valsartan or another angiotensin receptor blocker (ARB), which also relax arteries and veins;

  • Thiazide diuretics, informally called water pills, that reduce the kidneys ability to absorb salt;

  • Amlodipine and other calcium channel blockers, or CCB. Calcium causes the heart to squeeze more strongly, and by blocking calcium, these drugs lower blood pressure by keeping the blood vessels relaxed and open.

The race-based guidelines directed physicians to use only water pills or calcium-channel blockers with Black patients but to choose from among all four for non-Black patients. This limitation could prove harmful for Black patients because they may have undiagnosed kidney disease, and the ACEI and ARB medications are often prescribed to slow down the progression of kidney problems.

The UCSF researchers said they found that Black and non-Black patients had about the same median blood pressure and that there was more variation in hypertension control within groups using the same drug regimens than there was between Black and non-Black patients.

“It’s clear that selection of hypertension medication should be tailored to the individual, rather than driven by considerations of race,” said Dr. Michael B. Potter, a professor of family and community medicine and director of the Clinical and Translational Science Institute at UCSF. “Physicians shouldn’t settle for anything else but excellent blood pressure control in their patients and should make use of all available options to achieve this.”

Rather than race, doctors should focus on factors such as the dosage of the medication, the addition of second or third drugs, medication adherence, dietary and lifestyle interventions, as well as social and environmental challenges like the lack of access to healthy food, unstable housing, social isolation or difficulties paying bills.

“Race provides a poor proxy for precision medicine,” said Holt, who now practices at the University of Illinois Chicago. “Our study provides evidence that race-based prescribing is ineffective, unwarranted and may even be detrimental to Black patients in the long run.”

Data did show, though, that Black patients fared better at controlling their blood pressure when they had more frequent encounters with clinical staff, the researchers said.