Department of Medicine, Imperial College London, London, UK.
Chelsea and Westminster Hospital, London, UK.
HIV Med. 2018 Jan;19(1):1-6. doi: 10.1111/hiv.12528. Epub 2017 Jun 28.
The National Health Service in England (NHS England) does not provide pre-exposure prophylaxis (PrEP) against HIV, forcing people to purchase generic versions on the internet. However, there are concerns about the authenticity of medicines purchased online. We established an innovative service offering plasma tenofovir (TFV) and emcitrabine (FTC) therapeutic drug monitoring for people buying generic PrEP online, to ensure that drug concentrations in vivo were consistent with those of propriety brands and previously published data.
TFV/FTC concentrations were measured by ultra-performance liquid chromatography ultraviolet detection. Evaluation of renal function and testing for HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) were also carried out, at baseline and every 3-6 months, with risk reduction advice.
A total of 293 individuals presented having purchased PrEP on the internet: 85% were white, 84% were taking daily PrEP, and 16% were event-driven. Most were on generic TFV disoproxil fumarate (TDF)/FTC from Cipla Ltd. Median (range) TFV and FTC plasma concentrations were 104 (21-597) ng/mL and 140 (17-1876) ng/mL, respectively. All concentrations were above our established plasma TFV and FTC targets, based on previously published data. Renal function was normal in all evaluable individuals and no new cases of HIV, HBV or HCV infection were seen.
In a population at high risk of HIV acquisition, who cannot yet access PrEP on the NHS, concentrations of TFV and FTC in generic formulations purchased over the internet were similar to (or slightly higher than) those measured in phase I studies with the original formulation from Gilead (Truvada™), which has demonstrated high levels of protection against HIV infection in previous PrEP clinical trials.
英国国民保健署（NHS England）不提供艾滋病毒暴露前预防（PrEP），迫使人们在互联网上购买仿制药。然而，人们对网上购买的药品的真实性存在担忧。我们建立了一项创新服务，为在网上购买仿制药 PrEP 的人提供血浆替诺福韦（TFV）和恩曲他滨（FTC）治疗药物监测，以确保体内药物浓度与专有品牌和以前发表的数据一致。
通过超高效液相色谱紫外检测法测量 TFV/FTC 浓度。还在基线和每 3-6 个月进行肾功能评估和艾滋病毒、乙型肝炎病毒（HBV）和丙型肝炎病毒（HCV）检测，并提供减少风险建议。
共有 293 人在网上购买了 PrEP：85%是白人，84%每天服用 PrEP，16%是事件驱动的。大多数人服用的是 Cipla Ltd. 生产的仿制药替诺福韦二吡呋酯（TDF）/FTC。中位（范围）TFV 和 FTC 血浆浓度分别为 104（21-597）ng/mL 和 140（17-1876）ng/mL。所有浓度均高于我们根据以前发表的数据建立的血浆 TFV 和 FTC 目标。所有可评估的个体肾功能均正常，未发现新的 HIV、HBV 或 HCV 感染病例。
在一群无法在国民保健署获得 PrEP 的高艾滋病毒感染风险人群中，从互联网购买的仿制药中 TFV 和 FTC 的浓度与（或略高于）使用 Gilead（Truvada™）原始配方进行的 I 期研究中测量的浓度相似，该原始配方在以前的 PrEP 临床试验中已证明对艾滋病毒感染有高度保护作用。
