Treatment with tenofovir has an adverse impact on kidney function, but the clinical significance of this is modest, according to the results of a systematic review and meta-analysis conducted by an international team of investigators and published in the September 1st edition of Clinical Infectious Diseases.
The investigators looked at the results of 17 studies involving a total of 11,000 patients. All the studies compared outcomes in patients taking tenofovir-containing regimens to those seen in patients whose HIV treatment did not include this drug. Loss of kidney function was significantly greater amongst patients who took a combination of drugs that included tenofovir. In addition, those taking tenofovir were more likely to develop kidney disease.
However, the investigators comment: “Although our review identified a significant loss of renal function associated with TDF [tenofovir] use, the clinical magnitude of this effect was modest.”
Tenofovir (Viread, also in the combination pills Truvada and Atripla) is a widely-used antiretroviral drug in both industrialized and resource-limited settings. The clinical trials that formed the basis of the drug’s formal approval showed that it was very safe.
Nevertheless, after its licensing, case reports were published showing that some patients treated with the drug had developed kidney dysfunction or disease. Moreover, several observational cohort studies have founded that approximately 1% of tenofovir-treated patients per year develop such severe kidney dysfunction that they cease therapy with the drug.
Patients who are taking antiretroviral drugs in the UK and similar countries are recommended to have their kidney function monitored at regular intervals. However, such monitoring is impractical and unaffordable in many poorer countries.
Systematic review and meta-analysis: renal safety of tenofovir disoproxil fumarate in HIV-infected patients.
Ryan D. Cooper, Natasha Wiebe, Nathaniel Smith, Philip Keiser, Saraladevi Naicker, and Marcello Tonelli.
Clinical Infectious Diseases 51: 496-505, 2010. DOI: 10.1086/655681
Link to CID abstract