Concerns are growing that tenofovir, a widely prescribed antiretroviral HIV drug, could increase the likelihood that a patient will suffer kidney damage. According to a new study conducted by the San Francisco VA Medical Center, use of tenofovir could up the risk of kidney damage by 34 percent every year that a patient takes the medication.
Tenofovir is an antiretroviral drug that is taken daily, usually in a single pill combined with other drugs to prevent the development of full-blown AIDS in patients with HIV. However, according to a report from the San Francisco Chronicle, public health experts have begun to promote the drug for healthy individuals after recent research showed that tenofovir could prevent HIV infection. Kidney damage has long been a known risk of antiretroviral drugs like tenofovir, but how great a risk patients face, and even whether such side effects are caused by a particular drug, drug combo, or HIV itself, is the subject debate.
The VA study is one of the largest to address the long-term risks of tenofovir, and involved over 10,000 HIV-positive male and female veterans, the Chronicle reported. They had all started antiretroviral therapy from 1997 to 2007; 4,303 of those patients took tenofovir at some point. According to the study, the risk of developing a symptom of kidney damage – protein in the urine, rapid decline in kidney function and chronic kidney disease – increased by 11 to 34 percent each year, and patients’ risk remained elevated even after they stopped taking it.
“Does this mean that all patients on tenofovir need to be stopped? No,” Dr. Michael Horberg, director of HIV/AIDS at Kaiser Permanent, told the Chronicle. “What it does mean is you need to be monitoring these patients closely. You need to be checking kidney function, and if the signs are trending toward worsening function, consider alternatives.”
For people with HIV, the benefits of tenofovir – preventing the development of AIDS – mostly likely still outweigh its risk, the Chronicle said. But the new findings could dampen enthusiasm for tenofovir as an HIV preventative, though more research is needed. In the most recent prevention study, involving 2,500 men who did not have HIV, only a small number of participants showed signs of kidney damage. Their symptoms went away once they stopped taking tenofovir.
“The (VA) study was done in HIV-positive patients, and we don’t know whether the findings apply to HIV-uninfected people who are taking tenofovir for prevention,” Dr. Albert Liu, director of HIV prevention intervention studies at the San Francisco Department of Public Health, told the Chronicle