Renal safety of tenofovir containing antiretroviral regimen in a Singapore cohort

Tenofovirdisoproxilfumarate (TDF) is a nucleotide analogue widely recommended in international HIV treatment guidelines. The association of TDF and renal dysfunction has remained an area of interest.

We conducted a retrospective review of all patients on TDF from July 2007 to December 2009 in our institution and evaluated their renal function. Absolute change of creatinine clearance (CL_Cr) using Cockroft-Gault equation from baseline was calculated at 6, 12, 18 and 24 months. Overall, 226 patients were included in the study. Ninety percent were male. The median age was 46 yrs old (23–82), median weight was 60 kg (IQR 53.75-68), median CD4 count was 127 cells/mm³ (IQR 38–258) and median CL_Cr 82.7 mL/min (IQR 71.4-101.7) on initiation of TDF. The median decline of CL_Cr from baseline was −3.9 ml/min (IQR −12.3 to 7.6), and −3.6 ml/min (IQR −12.4 to 6.7) at 12 (n = 102), 24 months (n = 75) respectively. Eighteen of 226 patients had a decline in renal function to </=50 ml/min. Majority of which had an improvement of CL_Cr on follow up. Only 80% of patients ever received monitoring of renal function.

While we noted renal toxicity to be rare and transient among our cohort receiving TDF as part of their ARV regimen, these results reflect the short term renal effects of TDF given that ARV treatment is lifelong. Given that laboratory monitoring may be difficult to implement in many situations, future prospective studies looking into an evidence based algorithm for less frequent renal function monitoring than current guideline recommendations may be helpful.