[55] INCREASES IN CREATININE DURING THERAPY WITH TENOFOVIR DF

2nd International AIDS Society Conference on HIV Pathogenesis and Treatment

Paris, France - July 13 - 16, 2003

[TITLE:] INCREASES IN CREATININE DURING THERAPY WITH TENOFOVIR DF

[AUTHOR(S):] M Harris¹, B Yip¹, N Zalunardo², R Werb², M Valyi¹, R Hogg¹ and J Montaner¹
¹British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada; and ² Department of Nephrology, St Paul’s Hospital, Vancouver, Canada

IAS Conf HIV Pathog Treat 2003 Jul 13-16;2nd: Abstract No. 55
Antiviral Therapy 2003; 8(Suppl. 1):S197

[ABSTRACT:] The purpose of this study was to describe rates of clinically significant creatinine (Cr) increases in patients receiving tenofovir DF (TDF) in clinical practice. Demographic and laboratory data were extracted from the B.C. Centre for Excellence Drug Treatment Program (CfEDTP) database up to December 31, 2002. 476 HIV-infected adults started TDF in our clinic between 12/2001 and 12/2002. By 02/2003, 6 (1.3%) had discontinued TDF due to elevated Cr after a median of 4 months (range 2–9). Among patients with available laboratory results in the CfE-DTP database, the product limit estimate of the cumulative rate of Cr>1.5x baseline was 7.1%+1.9% at 6 months for patients taking TDF (n=322), as compared with 3.1%+0.9% for patients taking an abacavir (ABC)-containing regimen without TDF (n=430; P=0.003). At baseline the TDF and ABC groups had similar Cr (80 vs 82 µmol/l, P=0.18), proportions of patients with Cr>133 µmol/l (3.1% vs 3.7%, P=0.65) and proportions with AIDS (33.9% vs 29.8%, P=0.23). The TDF group had a marginally lower proportion of males (P=0.074), were older (P<0.001), had a longer median time on previous ARVs (P<0.001), and had a lower VL (P<0.001) and a higher CD4 cell count (median 230 vs 190/mm³, P<0.001) than the ABC group. In univariate analysis, earlier time to onset of elevated Cr was associated with TDF (P=0.004), prior AIDS (P=0.032), lower CD4 (P=0.001) and longer time on ARVs previously (P=0.072), but not with age, gender, VL, or baseline Cr (in this population where 96.5% had normal Cr at baseline). In multivariate analysis, earlier time to onset of elevated Cr was associated with TDF (RR 2.54, P=0.011) and lower CD4 (RR 1.45/100 cell decrement, P=0.001). In summary, clinically significant Cr increases were observed in 7% of patients taking TDF for 6 months, resulting in at least 1% of patients discontinuing TDF during the first year. Among patients with normal renal function at baseline, those with more advanced HIV disease are at higher risk of developing elevated Cr levels while taking TDF.

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