The potential long-term toxic effects of tenofovir on renal function have not been widely studied in large clinical and managed care cohorts, according to the authors.
“This study, which looks at a population of patients in a large
integrated care delivery system, indicates that there is a statistically
significant effect of tenofovir on renal function in patients who have
never been on antiretroviral medications previously and are now
initiating antiretroviral therapy,” said Michael Horberg, director of
HIV/AIDS for Kaiser Permanente and lead researcher for this study. He
added that the researchers also found that tenofovir exposure was
associated with a great risk of developing proximal tubular dysfunction,
another potential harm to the kidneys.
“The potential long-term adverse affects on kidney function may limit
use of tenofovir for patients risk for renal complications. Also,
long-term monitoring of renal function and proximal tubular dysfunction
in patients taking tenofovir should be considered.”
Researchers performed a retrospective cohort analysis of HIV infected
patients in California, Maryland, Virginia and the District of Columbia.
All were Kaiser Permanente patients initiating a first ART regimen from
January 2002 through December 2005. While the researchers note that
this topic warrants additional longer-term studies, the study is
significant for its patient population size, persistence of the adverse
renal effects over time, and the ability to control for a variety of
co-founders potentially associated with renal dysfunction, such as
patient demographics, co-morbidities and other medications prescribed.
Additional authors on the study include Beth Tang, MA, with the Kaiser
Permanente Center for Research and evaluation; William Towner, MD, an
HIV Medicine specialist at Kaiser Permanente in Los Angeles, CA; Michael
Silverberg, PHD, with the Kaiser Permanente Division of Research; Susan
Bersoff-Matcha, MD, with the department of infectious diseases at
Kaiser Permanente in Rockville Maryland; Leo Hurley, MPH, with the
Kaiser Permanente Division of Research; Joseph Chang, PharmD, with
Kaiser Permanente in Los Angeles; Jackie Blank, MBA, with Kaiser
Permanente in Rockville Maryland; Charles Quesenberry, PhD, with the
Kaiser Permanente Division of Research; and Daniel Klein, MD, with the
department of infectious diseases at Kaiser Permanente in Hayward, CA.
Funding for this study was provided by Gilead Sciences, Inc.