With transgender participation in sports a source of controversy in the upcoming election, a new study calling for more research into the effects of gender-affirming treatments highlights how the enduring consequences of underlying biology continue to impact this community.
The research, published this week in the journal Trends in Pharmacological Sciences, led by Lauren Cirrincione from the University of Washington, describes the existing knowledge gap about interactions between commonly prescribed drugs and hormone therapy.
“Despite established effects of sex steroids on drug metabolising enzyme expression and activity in vitro and in animal models, the effect of long-term, supraphysiologic sex hormone treatment on drug metabolism in transgender adults is not yet established,” Ms Cirrincione said.
“In short, we don’t know how gender-affirming hormone treatments interact with commonly prescribed drugs.”
Sex steroids, such as estrogen or testosterone, are commonly prescribed as a part of hormone replacement therapy for transgender patients and in both transgender and cisgender adults, sex steroids regulate enzymes involved in the detoxification step of drug metabolism.
These enzymes are known to metabolise several commonly prescribed drugs, including anti-HIV agents like protease inhibitors and other antiretrovirals, the antidepressant bupropion, the opioid analgesic methadone, and even drugs as ordinary as acetaminophen.
Research in cisgender adults already shows that genetic variability in these enzymes can impact an individual’s response to these drugs and continued ignorance may lead to unintended side effects in transgender individuals when prescribing treatments.
“In a population of people who often have altered concentration of sex steroids, further study is needed to understand the impact on drug metabolism,” Ms Cirrincione said.
The study comes on the heels of the release of the Australian Informed Consent Standards of Care for Gender Affirming Hormone Therapy by the Australian Professional Association for Trans Health (AusPATH), to mark Trans Day of Visibility on the 31st of March.
The new national Standards of Care are intended to assist and enable clinicians across Australia to better meet the medical gender affirmation needs of their trans women, trans men and non-binary patients.
The transgender population encounters numerous barriers to receiving proper medical care -even when treatment is accessible, healthcare providers may lack comprehensive knowledge on how to treat them either due to insufficient training or lack of information available.
Access to gender-affirming interventions in Australia typically follows one of two pathways; either a formal assessment and approval by a mental health professional as per the World Professional Association for Transgender Health Standards of Care, or by informed consent model of care where a decision to commence gender-affirming hormones is shared between a primary care general practitioner and a trans individual without mandating a formal mental health re-view.[1]
The Standards state that informed consent models of hormone prescribing “resist the notion that a doctor can determine the validity of a person’s gender, and instead centre the trans person in the decision-making process, whilst ensuring that the patient understands and can consent to the potential impacts that gender affirming hormone therapy may have on their body and life.”
Importantly, they also stipulate that when trans people attend clinical services seeking medical care, it is important to avoid pathologising the trans experience; “being trans is not a mental illness, it is an aspect of human variation, and hormones and surgery are not necessarily desired by all trans people.”
[1] Bretherton et al. (2021). The Health and Well-Being of Transgender Australians: A National Community Survey. LGBT Health. Vol 8:1. Mary Ann Liebert Inc. Page 43. DOI:10.1089/lgbt.2020.0178.