Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus , Aurora, CO, USA.
Expert Opin Drug Metab Toxicol. 2020 Jun;16(6):463-474. doi: 10.1080/17425255.2020.1752662. Epub 2020 Apr 21.
Transgender persons are at increased risk of HIV infection and would benefit from pre-exposure prophylaxis (PrEP) use. However, barriers to healthcare and a lack of data regarding PrEP efficacy among transgender persons limits use. A related issue is whether a drug-drug interaction (DDI) exists between gender affirming hormone therapy (GAHT) and PrEP. Recently, small pharmacokinetic studies were conducted to assess this interaction.
This review will assess the pharmacology of PrEP agents, existing data regarding potential DDIs between GAHT and PrEP, and hypothetical mechanisms for these DDIs. A summary will be provided on implications for PrEP use among transgender persons.
Theoretically, DDIs are not expected between GAHT and PrEP. However, among transgender women (TGW) on GAHT, small studies identified a minor DDI between GAHT and tenofovir/emtricitabine (TFV/FTC), with TFV/FTC exposures ~12-27% lower among TGW vs. cisgender men. The mechanism of DDIs is unclear and requires further study. For perspective, median TFV/FTC concentrations were still within the range of median concentrations reported across controlled pharmacokinetic studies. TFV-disphosphate/FTC-triphosphate concentrations were similar between TGW and cisgender men. In summary, TDF/FTC likely reaches protective concentrations and should continue to be offered as PrEP for transgender persons.
跨性别者感染 HIV 的风险增加，将受益于暴露前预防（PrEP）的使用。然而，跨性别者获得医疗保健的障碍以及缺乏关于 PrEP 疗效的数据限制了其使用。一个相关的问题是性别肯定激素治疗（GAHT）和 PrEP 之间是否存在药物-药物相互作用（DDI）。最近，进行了一些小型药代动力学研究来评估这种相互作用。
本综述将评估 PrEP 药物的药理学、GAHT 和 PrEP 之间潜在的 DDI 现有数据，以及这些 DDI 的假设机制。还将提供关于跨性别者使用 PrEP 的影响的总结。
从理论上讲，GAHT 和 PrEP 之间不应存在 DDI。然而，在接受 GAHT 的跨性别女性（TGW）中，一些小型研究发现 GAHT 和替诺福韦/恩曲他滨（TFV/FTC）之间存在轻微的 DDI，与顺性别男性相比，TGW 中的 TFV/FTC 暴露量降低了 12-27%。DDI 的机制尚不清楚，需要进一步研究。从观点来看，中位 TFV/FTC 浓度仍在对照药代动力学研究报告的中位数浓度范围内。TFV-二磷酸/FTC-三磷酸浓度在 TGW 和顺性别男性之间相似。总之，TDF/FTC 可能达到了保护浓度，应继续为跨性别者提供 PrEP。
