title: Antiretroviral prophylaxis for HIV infection in injecting drug users in Bangkok, Thailand (the Bangkok Tenofovir Study): a randomised, double-blind, placebo-controlled phase 3 trial.
abstract: BACKGROUND
  Antiretroviral pre-exposure prophylaxis reduces sexual transmission of HIV. We assessed whether daily oral use of tenofovir disoproxil fumarate (tenofovir), an antiretroviral, can reduce HIV transmission in injecting drug users.
  
  
  METHODS
  In this randomised, double-blind, placebo-controlled trial, we enrolled volunteers from 17 drug-treatment clinics in Bangkok, Thailand. Participants were eligible if they were aged 20-60 years, were HIV-negative, and reported injecting drugs during the previous year. We randomly assigned participants (1:1; blocks of four) to either tenofovir or placebo using a computer-generated randomisation sequence. Participants chose either daily directly observed treatment or monthly visits and could switch at monthly visits. Participants received monthly HIV testing and individualised risk-reduction and adherence counselling, blood safety assessments every 3 months, and were offered condoms and methadone treatment. The primary efficacy endpoint was HIV infection, analysed by modified intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00119106.
  
  
  RESULTS
  Between June 9, 2005, and July 22, 2010, we enrolled 2413 participants, assigning 1204 to tenofovir and 1209 to placebo. Two participants had HIV at enrolment and 50 became infected during follow-up: 17 in the tenofovir group (an incidence of 0·35 per 100 person-years) and 33 in the placebo group (0·68 per 100 person-years), indicating a 48·9% reduction in HIV incidence (95% CI 9·6-72·2; p=0·01). The occurrence of serious adverse events was much the same between the two groups (p=0·35). Nausea was more common in participants in the tenofovir group than in the placebo group (p=0·002).
  
  
  CONCLUSIONS
  In this study, daily oral tenofovir reduced the risk of HIV infection in people who inject drugs. Pre-exposure prophylaxis with tenofovir can now be considered for use as part of an HIV prevention package for people who inject drugs.
  
  
  BACKGROUND
  US Centers for Disease Control and Prevention and the Bangkok Metropolitan Administration.
authors.affiliation: Bangkok Tenofovir Study Group, Bangkok, Thailand.
authors.forename: Kachit
authors.initials: K
authors.lastname: Choopanya
authors.forename: Michael
authors.initials: M
authors.lastname: Martin
authors.forename: Pravan
authors.initials: P
authors.lastname: Suntharasamai
authors.forename: Udomsak
authors.initials: U
authors.lastname: Sangkum
authors.forename: Philip A
authors.initials: PA
authors.lastname: Mock
authors.forename: Manoj
authors.initials: M
authors.lastname: Leethochawalit
authors.forename: Sithisat
authors.initials: S
authors.lastname: Chiamwongpaet
authors.forename: Praphan
authors.initials: P
authors.lastname: Kitisin
authors.forename: Pitinan
authors.initials: P
authors.lastname: Natrujirote
authors.forename: Somyot
authors.initials: S
authors.lastname: Kittimunkong
authors.forename: Rutt
authors.initials: R
authors.lastname: Chuachoowong
authors.forename: Roman J
authors.initials: RJ
authors.lastname: Gvetadze
authors.forename: Janet M
authors.initials: JM
authors.lastname: McNicholl
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Paxton
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Curlin
authors.forename: Craig W
authors.initials: CW
authors.lastname: Hendrix
authors.forename: Suphak
authors.initials: S
authors.lastname: Vanichseni
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use*; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D000068698:Tenofovir; D013785:Thailand / Q000453:epidemiology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine