Lancet ：研究称泰诺福韦可降低吸毒者感染艾滋病毒风险

泰国和美国的最新联合研究成果显示，每日定时服用抗逆转录病毒药物泰诺福韦，可有效降低通过注射方式吸毒者感染艾滋病病毒的风险。

这一研究项目由泰国卫生部、美国疾病控制和预防中心研究人员从2005年开始共同实施。报告已发表在英国《柳叶刀》杂志上。泰诺福韦是艾滋病鸡尾酒疗法所采用的药物之一，它通过阻断涉及艾滋病病毒复制的逆转录酶，从而抑制病毒复制。

研究人员说，他们从泰国首都曼谷的17家戒毒机构选取2400多名未感染艾滋病毒的注射吸毒者为研究对象，他们年龄在20岁至60岁之间。研究对象被随机均分为两组，一组人每日定时服用泰诺福韦，另一组只服用安慰剂。实验表明，第一组中有17人感染艾滋病病毒，第二组有33人。也就是说，每日服用泰诺福韦可使注射吸毒者感染艾滋病病毒的几率降低49％。

报告说，2011年全球新增250万艾滋病毒病感染者，其中10％可能是吸毒所致。在泰国的艾滋病病毒感染者中，30％至50％的人为注射吸毒者。

先前已有研究表明，泰诺福韦可有效降低高危人群感染艾滋病病毒的风险。这次研究则首次证明，这种药物对注射吸毒人群也有预防效果。

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
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.
Findings
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).
Interpretation
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.
Funding
US Centers for Disease Control and Prevention and the Bangkok Metropolitan Administration.