Objectives
Tenofovir disoproxil fumarate (TDF) has been associated with renal insufficiency. Co-administration with boosted protease inhibitors (PIs), which increases its exposure, may further increase the risk of renal insufficiency.
Methods
We compared the incidence of renal events among women taking TDF co-administered with lopinavir/ritonavir (LPV/r) versus those co-administering TDF with nevirapine (NVP). Renal events were defined as a confirmed drop in creatinine clearance associated with a serum creatinine grade 2 or higher, or that leading to treatment modification.
Results
Overall, 741 HIV-infected women were enrolled into the study. Of these, 24 (3.2%) had reportable renal events (18 in LPV/r arm, 6 in NVP arm). In multivariate analysis, renal events were significantly associated with the LPV/r arm (odds ratio [OR]=3.12, 95% confidence interval [CI] 1.21, 8.05]; p=0.019), baseline HIV-1 RNA (OR=2.65, 95% CI: 1.23, 5.69 per 1 log10 copies/mL higher; p=0.013) and baseline creatinine clearance (OR=0.83, 95% CI 0.70–0.98 per 10 mL/min higher; p=0.030). In multivariate analysis evaluating renal events requiring treatment modification, only baseline HIV-1 RNA and creatinine clearance were significantly associated (OR=4.41, 95% CI 1.65, 11.78 per 1 log10 copies/mL higher; p= 0.003 and OR=0.80, 95% CI 0.64, 0.99 per 10 mL/min higher; p= 0.040, respectively).
Conclusion
The rates of renal events were relatively low in the two treatment arms. However, patients taking TDF co-administered with LPV/r had significantly more renal events compared to those co-administered with NVP. Furthermore, higher baseline HIV RNA and lower creatinine clearance were associated with the development of renal insufficiency requiring treatment modification.