title: Differences in nephrotoxicity risk and renal effects among anti-viral therapies against hepatitis B.
abstract: BACKGROUND
  Results are conflicting with respect to the renal effects of anti-viral agents used for hepatitis B virus infection.
  
  
  OBJECTIVE
  To compare short and long-term renal effects in real-life settings and to determine risk factors for renal impairment during treatment.
  
  
  METHODS
  2221 treatment-naïve patients were enrolled. Among these, 895 (302 lamivudine, 27 telbivudine, 282 entecavir, 273 tenofovir and 11 adefovir initiated patients) had 'repeated measures' of creatinine (baseline, 1st, 6th, 12th and 24th month of treatment). Telbivudine and adefovir groups were excluded from further analysis because of the low number of patients. We calculated the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) formula at each time point. Hypophosphataemia was also recorded. Risk factors for renal impairment were analysed.
  
  
  RESULTS
  Tenofovir caused a decline in GFR at each time point when compared to baseline levels. However, lamivudine and entecavir did not change GFR. GFR-shifting from ≥90 to 60-89 mL/min/1.73 m(2) was comparable among groups. The proportion of patients whose baseline creatinine increased more than 25% was comparable among all anti-virals. GFR showed a decline in patients who switched from entecavir to tenofovir. One patient with compensated cirrhosis needed to change from tenofovir because of renal safety. Seven and three patients developed transient hypophosphataemia in the tenofovir and lamivudine groups, respectively.
  
  
  CONCLUSIONS
  Although tenofovir caused a decline in GFR, differences between the anti-viral agents do not appear to be so impressive. In patients with and without renal risk factors at baseline, there is no impact of anti-virals, including tenofovir.
authors.affiliation: Department of Gastroenterology, Hacettepe University School of Medicine, Ankara, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Koklu
authors.affiliation: Gaziantep, Turkey.
authors.forename: M T
authors.initials: MT
authors.lastname: Gulsen
authors.affiliation: Antalya, Turkey.
authors.forename: Y
authors.initials: Y
authors.lastname: Tuna
authors.affiliation: Ankara, Turkey.
authors.forename: H
authors.initials: H
authors.lastname: Koklu
authors.affiliation: Ankara, Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Yuksel
authors.affiliation: Hatay, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Demir
authors.affiliation: Ankara, Turkey.
authors.forename: R
authors.initials: R
authors.lastname: Guner
authors.affiliation: Ankara, Turkey.
authors.forename: Z
authors.initials: Z
authors.lastname: Dogan
authors.affiliation: Ankara, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Kucukazman
authors.affiliation: Kayseri, Turkey.
authors.forename: O K
authors.initials: OK
authors.lastname: Poyrazoglu
authors.affiliation: Konya, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Biyik
authors.affiliation: Adana, Turkey.
authors.forename: N A
authors.initials: NA
authors.lastname: Ozturk
authors.affiliation: Sanliurfa, Turkey.
authors.forename: T
authors.initials: T
authors.lastname: Aydogan
authors.affiliation: Ankara, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Coban
authors.affiliation: Istanbul, Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Kocaman
authors.affiliation: Kirikkale, Turkey.
authors.forename: F
authors.initials: F
authors.lastname: Sapmaz
authors.affiliation: Konya, Turkey.
authors.forename: S H
authors.initials: SH
authors.lastname: Gokturk
authors.affiliation: Istanbul, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Karaca
authors.affiliation: Ankara, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Demirezer
authors.affiliation: Istanbul, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Tanoglu
authors.affiliation: Samsun, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Yildirim
authors.affiliation: Ankara, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Altinbas
authors.affiliation: Isparta, Turkey.
authors.forename: B M
authors.initials: BM
authors.lastname: Atak
authors.affiliation: Trabzon, Turkey.
authors.forename: A M
authors.initials: AM
authors.lastname: Cosar
authors.affiliation: Antalya, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Alkan
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D003404:Creatinine / Q000378:metabolism; D005260:Female; D005919:Glomerular Filtration Rate; D006515:Hepatitis B virus / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D008103:Liver Cirrhosis / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000139:chemically induced* / Q000453:epidemiology; D012306:Risk
chemical_list: D000998:Antiviral Agents; D003404:Creatinine