Risk of estimated glomerular filtration rate decline not adjusted for body surface area with tenofovir disoproxil fumarate use

Abstract

Objective: The dose of tenofovir disoproxil fumarate (TDF) requires an adjustment in patients with renal dysfunction. However, a combination tablet containing TDF is often prescribed to improve medication adherence, which makes TDF dose adjustment difficult. In fact, the discontinuation of TDF has been observed based on the estimated glomerular filtration rate (eGFR) decline not adjusted for body surface area (BSA) in our hospital. Therefore, we focused on evaluating the eGFR without a BSA adjustment (unadjusted eGFR) at the start of TDF administration to investigate the association between TDF exposure and the risk of unadjusted eGFR decline.Method: We retrospectively reviewed the clinical records of 21 patients infected with the human immunodeficiency virus (HIV) and receiving combination anti-retroviral therapy including TDF at our hospital between April 2005 and May 2014. Patients were divided into two groups based on the unadjusted eGFR: the more than (MT) and less than (LT) 80 mL/min groups at the start of TDF therapy. We compared the unadjusted eGFR, and other relevant factors between the two groups.Result: Of the 13 patients in the MT group, 12 tolerated TDF while only two of the eight patients in the LT group did, which indicated a significant difference between the two groups. Further, in patients who corresponded to a low-dose standard, a significant correlation was observed between the unadjusted eGFR level and TDF treatment duration.Consideration: In this study, the administration of TDF caused an unadjusted eGFR decline in patients (eGFR 50-80 mL/min), making the continuous administration of TDF difficult. Therefore, we recommended the implementation of careful medication consultation as well as drug fostering and evolution of TDF dose adjustment in high-risk patients (eGFR 50-80 mL/min).