Effect of changing from first- to second-line antiretroviral therapy on renal function: a retrospective study based on data from a single health facility in Namibia

Background: Tenofovir disoproxil fumarate (TDF) and lopinavir/ritonavir (LPV/r) can cause renal impairment with this combination co-administered during second-line combination antiretroviral therapy (cART) potentially associated with greater risk of nephrotoxicity. As a result, the aim of this study is to assess effects of second-line cART on renal function. Methods: Retrospective longitudinal study in patients receiving cART. Results: 71 patients received TDF, zidovudine or stavudine, each combined with 3TC/NVP or 3TC/EFV. Before second-line cART, 46.5% had abnormal kidney function. First-line cART had no relationship with calculated creatinine clearance (CrCl). During second-line cART, more males than females had abnormal renal function and more females experienced increases in CrCl. Calculated CrCl during second-line cART related strongly with CrCl during first-line cART. Time spent on cART weak had a week relationship with CrCl. Conclusion: Patients on first-line cART for several years without renal impairment may experience new onset impairment during second line cART. Patients with pre-existing renal impairment just before switching to second-line cART may experience a further decline.