Drug-drug Interactions Among Thai Transgender Women Living with Human Immunodeficiency Undergoing Feminizing Hormone Therapy and Antiretroviral Therapy: The iFACT Study

Lived experiences with pre-exposure prophylaxis uptake and adherence among transgender women in Thailand: a qualitative study

BACKGROUND

Transgender women (TGW) are disproportionately affected by HIV, and HIV prevalence among TGW in Thailand has been increasing. Although oral daily pre-exposure prophylaxis (PrEP) is effective for HIV prevention, PrEP uptake and persistence among TGW have been low. This study aimed to provide a deeper understanding of TGW's experiences with PrEP uptake and adherence, and to identify major barriers to PrEP use to inform intervention adaptation.

METHODS

We interviewed 20 young TGW (six non-PrEP users, eight adherent, six non-adherent) and 10 health care providers from two HIV clinics in Bangkok, Thailand, in 2022. We focused on understanding challenges to PrEP use in this population using an interview guide based on a theoretical model of behaviour change and thematic content analysis.

RESULTS

Thematic analysis identified major barriers to and facilitators of PrEP uptake and adherence. Barriers to PrEP initiation included low self-perceived HIV risk, concern about potential side-effects, patient burdens such as frequent HIV testing for prescription refills and social stigma against PrEP. Barriers to adherence included side-effects, inconvenient access to health services (especially during COVID-19 lockdowns), forgetfulness resulting from busy schedules and low self-perceived HIV risk. TGW also reported health care providers' stigma against PrEP users deterred them from seeking further PrEP services. TGW identified major facilitators of PrEP initiation, including awareness about the benefits of PrEP, concern about risks of HIV and supportive social networks of PrEP users. As to PrEP regimens, most TGW participants reported a clear preference for long-lasting, injectable PrEP over daily oral PrEP. TGW and health care providers largely agreed on barriers and facilitators of PrEP use, but they differed in perceptions of HIV risk.

CONCLUSIONS

The results highlighted challenges and opportunities to improve the delivery of PrEP, as well as other sexually transmissable infection and mental health services, especially among TGW. Thus, there is an urgent need for developing effective intervention programs that could raise PrEP awareness and knowledge, reduce PrEP stigma, and improve PrEP delivery systems among TGW in Thailand.

Human Immunodeficiency Virus as a Risk Factor for Cardiovascular Disease

The developments in HIV treatments have increased the life expectancy of people living with HIV (PLWH), a situation that makes cardiovascular disease (CVD) in that population as relevant as ever. PLWH are at increased risk of CVD, and our understanding of the underlying mechanisms is continually increasing. HIV infection is associated with elevated levels of multiple proinflammatory molecules, including IL-6, IL-1β, VCAM-1, ICAM-1, TNF-α, TGF-β, osteopontin, sCD14, hs-CRP, and D-dimer. Other currently examined mechanisms include CD4 + lymphocyte depletion, increased intestinal permeability, microbial translocation, and altered cholesterol metabolism. Antiretroviral therapy (ART) leads to decreases in the concentrations of the majority of proinflammatory molecules, although most remain higher than in the general population. Moreover, adverse effects of ART also play an important role in increased CVD risk, especially in the era of rapid advancement of new therapeutical options. Nevertheless, it is currently believed that HIV plays a more significant role in the development of metabolic syndromes than treatment-associated factors. PLWH being more prone to develop CVD is also due to the higher prevalence of smoking and chronic coinfections with viruses such as HCV and HBV. For these reasons, it is crucial to consider HIV a possible causal factor in CVD occurrence, especially among young patients or individuals without common CVD risk factors.

Assessing Knowledge of, Experience with, and Willingness to Prescribe Hormone Therapy to Transgender Individuals with HIV: A National Survey of HIV Practitioners

Purpose

The purpose of this study was to determine if human immunodeficiency virus (HIV) practitioners offer gender-affirming hormone therapy (GAHT) to their transgender patients living with HIV, as previous studies have shown that these patients are more likely to be virally suppressed and retained in care.

Methods

We conducted an online survey sent to 2570 HIV practitioners who attended an International Antiviral Society-USA event between 2017 and 2019. We also assessed demographics, transgender care training, comfort, prescribing practices, and knowledge.

Results

Respondents (N=385) were mainly primary care (49%) and infectious disease (ID)/HIV (42%) practitioners. Fifty-seven percent prescribed GAHT to transgender people living with HIV, but only 7% received formal training. Thirty-five percent were ID/HIV, 60% were primary care, and 5% were other specialty practitioners. Most felt that it would be beneficial to have formal education in GAHT practices during training (83%). There were statistically significant differences in GAHT education, experiences, knowledge, and interest in future training and prescribing by health care specialty. Commonly cited barriers to providing therapy included lack of training (33%), lack of transgender people living with HIV in practice (18%), and lack of qualified mental health professionals (15%).

Conclusion

This survey is the first to assess GAHT practices among HIV practitioners from across the United States. The majority of those surveyed prescribe GAHT to their transgender patients living with HIV. Although most felt comfortable doing so, few had formal training and knowledge scores were low. We advocate for the integration of GAHT education into formal training programs and offer resources for those who wish to pursue education.

Oestradiol concentrations in trans women with HIV suppressed on unboosted integrase inhibitor regimens versus trans women without HIV taking oral oestradiol: a pilot study

BACKGROUND

Feminizing hormone therapy (FHT) is essential to many trans women. Concern about negative drug interactions between FHT and ART can be an ART adherence barrier among trans women with HIV.

OBJECTIVES

In this single-centre, parallel group, cross-sectional pilot study, we measured serum oestradiol concentrations in trans women with HIV taking FHT and unboosted integrase strand transfer inhibitor (INSTI)-based ART versus trans women without HIV taking FHT.

METHODS

We included trans women with and without HIV, aged ≥18 years, taking ≥2 mg/day of oral oestradiol for at least 3 months plus an anti-androgen. Trans women with HIV were on suppressive ART ≥3 months. Serum oestradiol concentrations were measured prior to medication dosing and 2, 4, 6 and 8 h post-dose. Median oestradiol concentrations were compared between groups using Wilcoxon rank-sum tests.

RESULTS

Participants (n = 8 with HIV, n = 7 without) had a median age of 32 (IQR: 28, 39) years. Among participants, the median oral oestradiol dose was 4 mg (range 2-6 mg). Participants had been taking FHT for a median of 4 years (IQR: 2, 8). Six trans women with HIV were taking bictegravir/emtricitabine/tenofovir alafenamide and two were taking dolutegravir/abacavir/lamivudine. All oestradiol concentrations were not significantly different between groups. Eleven (73%) participants had target oestradiol concentrations in the range 200-735 pmol/L at C4h (75% among women with HIV, 71% among those without HIV).

CONCLUSIONS

Oestradiol concentrations were not statistically different in trans women with HIV compared with those without HIV, suggesting a low probability of clinically relevant drug-drug interactions between FHT and unboosted INSTI-based ART.

Estradiol and Spironolactone Plasma Pharmacokinetics Among Brazilian Transgender Women Using HIV Pre-Exposure Prophylaxis: Analysis of Potential Interactions

BACKGROUND AND OBJECTIVE

An important barrier to HIV prevention among transgender women (TGW) is the concern that oral pre-exposure prophylaxis (PrEP) negatively affects the efficacy of feminizing hormone therapy (FHT). We aimed to assess the impact of PrEP on FHT pharmacokinetics (PK) among TGW from Brazil.

METHODS

We performed a drug-drug interaction sub-study among TGW enrolled in a daily oral PrEP demonstration study (PrEParadas, NCT03220152). Participants had a first PK assessment (PK1) 15 days after FHT (estradiol valerate 2-6 mg plus spironolactone 100-200 mg) initiation and then started PrEP (tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg). A second PK evaluation was performed 12 weeks later (PK2). Blood samples were collected prior and after the directly observed dosing (0, 0.5, 1, 2, 4, 6, 8, and 24 hours). Pharmacokinetic parameters of estradiol, spironolactone, and metabolites were estimated by non-compartmental analysis (Monolix 2021R2, Lixoft®) and compared as geometric mean ratios (GMRs, 90% confidence interval [CI]).

RESULTS

Among 19 TGW who completed the substudy, median age was 26 years (interquartile range: 23-27.5). Estradiol area under the plasma concentration-time curve (AUCτ) and trough concentrations did not differ between PK1 and PK2 evaluations (GMR [90% CI]: 0.89 [0.76-1.04] and 1.06 [0.94-1.20], respectively). Spironolactone and canrenone AUCτ were statistically lower at PK2 than PK1 (0.76 [0.65-0.89] and 0.85 [0.78-0.94], respectively). Canrenone maximum concentration was also lower at PK2 than PK1 (0.82 [0.74-0.91]).

CONCLUSION

Estradiol PK was not influenced by PrEP concomitant use. The small differences observed in some spironolactone and canrenone PK parameters should not prevent the concomitant use of estradiol-based FHT and PrEP.

TRIAL REGISTRATION

This trial (NCT03220152) was registered on July 18, 2017.

Feminizing hormone therapy in a Canadian cohort of transgender women with and without HIV

BACKGROUND

Potential bidirectional drug-drug interactions between feminizing hormone therapy (FHT) and antiretroviral therapy (ART) are of concern for trans women with HIV and their healthcare providers. This study aimed to characterize patterns of FHT and ART among trans women with HIV and to compare serum hormone levels to trans women without HIV.

METHODS

Charts of trans women were reviewed at seven HIV primary care or endocrinology clinics in Toronto and Montreal from 2018 to 2019. ART regimens, FHT use, serum estradiol, and serum testosterone levels were compared on the basis of HIV status (positive, negative, missing/unknown).

RESULTS

Of 1495 trans women, there were 86 trans women with HIV, of whom 79 (91.8%) were on ART. ART regimens were most commonly integrase inhibitor-based (67.4%), many boosted with ritonavir or cobicistat (45.3%). Fewer (71.8%) trans women with HIV were prescribed FHT, compared to those without HIV (88.4%) and those with missing/unknown status (90.2%, p < 0.001). Among trans women on FHT with recorded serum estradiol (n = 1153), there was no statistical difference in serum estradiol between those with HIV (median: 203 pmol/L, IQR: 95.5, 417.5) and those with negative (200 mol/L [113, 407]) or missing/unknown HIV status (227 pmol/L [127.5, 384.5) (p = 0.633). Serum testosterone concentrations were also similar between groups.

CONCLUSIONS

In this cohort, trans women with HIV were prescribed FHT less often than trans women with negative or unknown HIV status. There was no difference in serum estradiol or testosterone levels of trans women on FHT regardless of HIV status, providing reassurance regarding potential drug-drug interactions between FHT and ART.

Mapping Community-Engaged Implementation Strategies with Transgender Scientists, Stakeholders, and Trans-Led Community Organizations

PURPOSE OF REVIEW

Pre-exposure prophylaxis (PrEP) represents one of the most effective methods of prevention for HIV, but remains inequitable, leaving many transgender and nonbinary (trans) individuals unable to benefit from this resource. Deploying community-engaged PrEP implementation strategies for trans populations will be crucial for ending the HIV epidemic.

RECENT FINDINGS

While most PrEP studies have progressed in addressing pertinent research questions about gender-affirming care and PrEP at the biomedical and clinical levels, research on how to best implement gender-affirming PrEP systems at the social, community, and structural levels remains outstanding. The science of community-engaged implementation to build gender-affirming PrEP systems must be more fully developed. Most published PrEP studies with trans people report on outcomes rather than processes, leaving out important lessons learned about how to design, integrate, and implement PrEP in tandem with gender-affirming care. The expertise of trans scientists, stakeholders, and trans-led community organizations is essential to building gender-affirming PrEP systems.

Regulation of drug-metabolizing enzymes by sex-related hormones: clinical implications for transgender medicine

Transgender medicine is a diverse and growing clinical field with unmet gaps in pharmacological knowledge. Hormone therapy (testosterone or estrogen treatment), one part of the standard of medical care for transgender adults, aligns secondary sex characteristics with an individual's gender identity and expression. Despite established effects of sex steroids on drug-metabolizing enzyme expression and activity in vitro and in animal models, the effect of long-term, supraphysiological sex hormone treatment on drug metabolism in transgender adults is not yet established. Here, we synthesize available in vitro and animal model data with pharmacological concepts in transgender medicine to predict potential effects of sex steroids on drug-metabolizing enzymes, and their relationship with potential hormone-drug interactions, in transgender medicine.

Navigating Human Immunodeficiency Virus and Primary Care Concerns Specific to the Transgender and Gender-Nonbinary Population

Human immunodeficiency virus (HIV) prevention and treatment remain critically important to outpatient care among transgender and gender-nonbinary individuals. Epidemiologically, trans men and trans women are significantly more likely to have HIV compared with all adults of reproductive age. Here, we provide an overview of unique primary care considerations affecting transgender and gender-nonbinary individuals, including screening and treatment of HIV and other sexually transmitted infections as well as cancer screening and fertility preservation options. We also seek to review current literature and clinical practice guidelines related to drug–drug interactions between antiretroviral therapy (ART) and gender-affirming hormonal therapy (GAHT). In short, integrase strand transfer inhibitor–based therapy is not expected to have significant drug interactions with most GAHT and is preferred in most transgender individuals, including those on GAHT. Clinicians should also remain aware of current GAHT regimens and consider tailoring ART and GAHT to reduce cardiovascular and other risk factors.

Cardiovascular Disease Risk Among Transgender People with HIV

PURPOSE OF REVIEW

Transgender individuals are at disproportionate risk for HIV infection, with prevalence rates highest among transgender women of color. Antiretroviral therapy (ART)-treated people with HIV (PWH) are at increased risk for cardiovascular disease (CVD), in relation to persistent systemic immune activation and metabolic dysregulation. The purpose of this review is to examine parameters which may affect CVD risk among transgender PWH.

RECENT FINDINGS

Among transgender women and men, prospective longitudinal studies have shown that gender-affirming hormonal therapy (GAHT) is associated with select deleterious cardiometabolic effects such as increases in visceral adipose tissue. Retrospective studies among transgender women and men suggest an increase in CVD risk, such as venous thromboembolism, cerebrovascular accidents, and myocardial infarction. Studies among transgender PWH adhering to GAHT and ART suggest heightened systemic immune activation/inflammation. Prospective longitudinal studies assessing factors associated with increased CVD events among transgender PWH are needed to guide the development of CVD prevention strategies in this at-risk population.

Sex and Gender Differences in Clinical Pharmacology: Implications for Transgender Medicine

The transgender adult population is growing globally, but clinical pharmacology has lagged behind other areas of transgender medicine. Medical care for transgender adults may include long‐term testosterone or estrogen treatment to align secondary sex characteristics with gender identity. Clinicians often use drug–drug interaction data from the general adult population to predict medication disposition or safety among transgender adults. However, this approach does not address the complex pharmacodynamic effects of hormone therapy in transgender adults. In this review, we critically examine sex‐related and gender‐related differences in clinical pharmacology and apply these data to discuss current gaps in transgender medicine.

Sex and Gender Differences in Clinical Pharmacology: Implications for Transgender Medicine

The transgender adult population is growing globally, but clinical pharmacology has lagged behind other areas of transgender medicine. Medical care for transgender adults may include long-term testosterone or estrogen treatment to align secondary sex characteristics with gender identity. Clinicians often use drug-drug interaction data from the general adult population to predict medication disposition or safety among transgender adults. However, this approach does not address the complex pharmacodynamic effects of hormone therapy in transgender adults. In this review, we critically examine sex-related and gender-related differences in clinical pharmacology and apply these data to discuss current gaps in transgender medicine.

Pharmacotherapy considerations in transgender individuals living with human immunodeficiency virus

Pharmacotherapy considerations are often a concern for transgender individuals who are living with human immunodeficiency virus (HIV) due to concerns for drug-drug interactions between their hormone and antiretroviral therapies. Many of the first-line therapies offered to patients for the management of HIV have reduced concerns for safety, resistance, and drug-drug interactions. In this review, we highlight common medications and important considerations for caring for transgender people living with HIV.

Drug Interactions with Gender-Affirming Hormone Therapy: Focus on Antiretrovirals and Direct Acting Antivirals

INTRODUCTION

Gender-affirming care may include hormonal therapy to attain desired health outcomes in transgender (trans) individuals. To provide safe, affirming medical care for trans patients, health care providers must identify and manage drug-drug interactions (DDIs) between gender affirming hormonal therapy (GAHT) and other medication therapies.

AREAS COVERED

This review summarizes available data on DDIs between GAHT and antiretrovirals (ARVs) or hepatitis C direct acting antivirals (DAAs). Potential pharmacokinetic and pharmacodynamic DDIs are predicted based on GAHT, ARV, and DAA pharmacology and adverse event profiles. Clinical management strategies are discussed.

EXPERT OPINION

GAHT may be involved in pharmacokinetic and/or pharmacodynamic DDIs. Certain ARV classes (non-nucleoside reverse transcriptase inhibitors, protease inhibitors) may alter GAHT disposition, whereas selected ARVs (unboosted integrase inhibitors, doravirine, or rilpivirine) may have less impact on GAHT. DAAs may interact with GAHT, but the clinical relevance is unclear. ARV- and/or DAA-associated side effects (including depression, cardiovascular disease, hyperlipidemia) are important to consider in the clinical management of trans patients. Clinicians must evaluate potential DDIs and overlapping side effects between ARVs, DAAs and GAHT when providing care for trans patients.