Tenofovir disoproxil fumarate (TDF) effectively suppresses viral replication in chronic hepatitis B (CHB), but occasionally leads to renal impairment. We evaluated the prevalence of viral and biochemical breakthrough and renal function kinetics in renally impaired patients with CHB on reduced and on full-dose TDF. This clinic-based longitudinal cohort study included patients receiving full and reduced dose TDF (due to eGFR [Cockcroft-Gault] <60 mL/min/1.73 m2). Viral and biochemical breakthroughs were assessed 1 month after starting full and reduced TDF dose until the end-of-follow-up. Breakthroughs were studied in full and reduced dose TDF, and renal function (MDRD) longitudinally before and after dose reduction within patients starting on full-dose TDF. Of 750 patients on TDF, 78 (10%) had reduced dose and 672 (90%) full dose. At the time of dose reduction, 36 (46%) patients had chronic kidney disease stage G3B. A viral breakthrough occurred in one cirrhotic dialysis-dependent patient (dosed 300 mg weekly) which resolved without signs of decompensation, and in one patient on full dose which resolved spontaneously. One biochemical breakthrough occurred during dose reduction and resolved naturally without viral breakthrough. The MDRD improved within the first year of dose reduction (+3.0 [2.5] mL/min per year; P <.005) and remained stable thereafter. Fifty-three (79%) patients reached an MDRD >50 mL/min during dose reduction. Low dose TDF maintains renal function and viral suppression in most renally impaired patients with CHB, even in those with advanced liver disease. This useful, yet simple strategy could be particularly viable in resource-constrained settings.
Bibliographical noteFunding Information:
This study was organized and sponsored by the Toronto Centre for Liver Disease (Toronto, Canada).
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