Reframing the Landscape for Achieving Equitable Pharmacotherapy Health Outcomes: Introducing Pharmacogenequity

The subfield of research attempting to ensure that precision medicine‐guided pharmacotherapy benefits diverse groups remains undefined. In this Perspective, I (1) reflect on and celebrate pharmacoequity as a rapidly expanding area of research and (2) propose pharmacogenequity to help delineate a distinct but parallel discipline. To do this, I anchor the discussion around preventing adverse drug events. Future endeavors that advance both fields together will enable comprehensive achievement of improved pharmacotherapeutic health outcomes for all.

Adverse drug events

Over the past several decades, the widespread use of prescription drugs has contributed to improved life expectancy for the over 200 million Americans who receive them yearly. However, widespread drug use has also increased the risk of adverse drug events. ¹ Adverse drug events are defined by the Institutes of Medicine as an “injury resulting from medical intervention related to a drug.” ¹ This broad definition includes injury from failure to receive a necessary drug as well as poor pharmacotherapeutic‐related outcomes, whether or not the therapy is taken.

Preventable adverse drug events

A large proportion of adverse drug events are considered to be preventable. These include adverse drug events due to medication errors (defined as “any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the medication healthcare professional, patient, or consumer”), ¹ which can be addressed broadly through system‐level interventions. Beyond medication errors, preventable adverse drug events also include those related to access. Examples that present as barriers to access are lack of adequate insurance and having no pharmacies within a feasible proximity. ²

Pharmacoequity to address disparities in preventable adverse drug events

Importantly, the subclass of preventable adverse drug events related to access is more likely to negatively affect patient groups from marginalized communities. In 2021, Essien et al. brilliantly summarized the state at which this health disparity is completely resolved. ² Briefly, they introduced a powerful new term to describe this idealistic achievement: pharmacoequity: when “all individuals, regardless of race and ethnicity, socioeconomic status, or availability of resources, have access to the highest‐quality medications required to manage their health needs.” They then highlighted how equitable access can be achieved through interventions such as those that enhance prescription drug coverage and eliminate pharmacy deserts. Pharmacoequity has resonated with many members of the scientific and clinical community. In a short time, its use as a search term in PubMed now pulls up > 60 publications to date. Additionally, it inspired the theme for the 2026 American Society of Clinical Pharmacology and Therapeutics (ASCPT) annual meeting. However, this term is likely more than just a trendy portmanteau. It seems to have captured the imagination of an entire research community across multiple disciplines each aiming for equity in prescription access within their respective fields. Pharmacoequity as both a buzzword and ideology is undoubtedly here to stay, deservedly so.

Adverse drug reactions

There is another class of adverse drug events that deserves recognition. Adverse drug reactions in particular are adverse drug events that occur when a drug is prescribed correctly at normal doses and administered to or by the patient appropriately as directed. ¹ Because adverse drug reactions occur despite the most optimal evidence‐based therapy and patient adherence, these adverse drug events are considered to be “nonpreventable.” ¹ It is difficult to estimate the prevalence of adverse drug reactions due to underreporting, but some sources indicate that they encompass ~70% of adverse drug events, ³ representing a tremendous burden on health care. Indeed, the most severe adverse drug reactions using conservative estimates lead to millions of hospitalizations yearly and are among the top six leading causes of death. ⁴ Adverse drug reactions occur because there is substantial interindividual variation in pharmacological response to a therapeutic agent even at the same dose, and this variability can impact health outcomes. Variation in pharmacological response can occur due to pharmacokinetic or pharmacodynamic effects. Polymorphisms in the genes that code for mediators of pharmacokinetics and pharmacodynamics (enzymes, transporters, and receptors) contribute to the variation in pharmacological response, sometimes in a clinically meaningful way. In addition to pharmacogenetic polymorphisms, multiple other factors (e.g., clinical, molecular, somatic mutations, and environmental) mediate the function of enzymes, transporters, and receptors. The greater the understanding of the factors that are attributed to this variation, the better we can prevent adverse drug reactions. Thus, even though adverse drug reactions are considered to be nonpreventable (at least during point of care), they in fact can be prevented: by generating evidence that redefines the standard of care. This is particularly the case when a dose considered normal in the general population elicits harm in patient subgroups. The strategy that seeks to understand the factors that impact drug response variation is known as precision medicine. Pharmacogenetics is a cornerstone of precision medicine. Preemptive pharmacogenetic prescribing has demonstrated efficacy in reducing the risk of adverse drug reactions; evidence is based on decades of reports demonstrating clinical validation for gene–drug response relationships as well as results from a landmark randomized controlled trial showing a 30% adverse drug reaction reduction. ⁵ Consequently, what started off as clinical pharmacogenetics implementation in a handful of early adopters has expanded into a global effort. ⁵

Adverse drug reactions and health disparities

Similar to access‐related adverse drug events, the burden of adverse drug reactions are also disproportionate to minoritized patient groups. This is true because scientists and clinicians have a much better understanding of the factors impacting drug variation in well‐studied groups. Results in these groups are often applied for the clinical care of patients from understudied groups. Sometimes the results of this practice is benign, but often the impact is harmful to those understudied groups. ⁶ When one group benefits from precision medicine at a higher rate than another group, this leads to health disparities as defined by the National Institute on Minority Health and Health Disparities (NIMHD): “a health difference, on the basis of one or more health outcomes, that adversely affects disadvantaged populations.” Thus, even if access‐related barriers to drugs such as insurance coverage and physical proximity were completely removed (i.e., pharmacoequity is achieved), disparities related to adverse drug reactions would still remain. To address this underappreciated issue, clinicians and scientists in the field of precision medicine have conducted studies prioritizing understudied patient groups in an attempt to capture factors that contribute to larger proportions of drug response variation globally. ⁷ , ⁸ The goal is for all patients to benefit from precision medicine.

Language matters

The subfield of research attempting to ensure that precision medicine‐guided pharmacotherapy benefits broad and diverse populations has made tremendous discoveries over the past decade. However, this subfield remains undefined (i.e., no framework or consistently used term exists to define it). Furthermore, terms such as precision health equity are broad and expand to subdisciplines outside of pharmacotherapy (e.g., disease diagnosis). Moreover, this space is completely siloed from that which studies equity in access to evidence‐based drugs and technologies (pharmacoequity). As someone whose work has operated in this undefined area, I have witnessed firsthand both the utility and the potential ambiguity of the term pharmacoequity. I myself have categorized my research under the pharmacoequity umbrella, ⁹ not because of perfect conceptual alignment, but because there was no better alternative. In retrospect, this was a missed opportunity to define a complementary space. Pharmacoequity captures a significant swath and an incredibly important aspect of achieving equity for pharmacotherapy outcomes. Nevertheless, the literature is quite clear that it was never intended to encompass areas outside of access ² including the work of myself and my colleagues. The aforementioned 2026 ASCPT annual meeting, while nominally focused on pharmacoequity, undoubtedly included material outside of this subdiscipline. For example, all 28 Presidential Trainee abstracts for this meeting (including those relevant to health disparities) were deeply grounded in principles of clinical pharmacology and precision medicine. Therefore, I propose the novel term pharmacogenequity to help delineate a distinct but parallel subdiscipline that deserves recognition in its own right for aiming to achieve equitable health outcomes related to pharmacotherapy.

Pharmacogenequity

While pharmacoequity is achieved once there are no health disparities for access‐related adverse drug events, pharmacogenequity is achieved when the same is true for adverse drug reactions. These terms do not describe novel concepts; efforts to achieve these goals have undoubtedly existed for decades. However, this new terminology helps to advance each respective subfield by improving conceptual clarity and unifying them under a shared framework. Both subfields require substantial research. For pharmacoequity, this could include qualitative research that better understands the lived experiences of people from marginalized communities and how that impacts access to drugs. Research for pharmacogenequity is rooted in precision medicine to determine the factors accounting for drug response variation. Traditional precision medicine at the status quo is not enough to achieve this state. Research for pharmacogenequity requires precision medicine studies with substantial ancestral diversity on a global scale, large sample sizes, and inclusion of drug biomarkers that have not been traditionally considered in precision medicine research (e.g., social determinants of health) with an emphasis on understudied patient groups. Therefore, both subdisciplines need to consider social determinants of health for optimal results. Both subdisciplines require thoughtful implementation tactics to successfully translate research findings into improved outcomes. For pharmacoequity, this would entail policy interventions that consider social determinants of health in addressing barriers to drug access. Pharmacogenequity would require incorporation of inclusive biomarkers into practice guidelines to inform clinical decision making, as we have previously done. ¹⁰ There are some pharmacogenetic studies that are within the realm of pharmacoequity such as those that investigate access to pharmacogenetic drugs or testing (i.e., health policy interventions would be needed to improve equity related to these outcomes). See Figure 1 for a visual depicting how these subfields are interrelated while asking separate questions, relying on different datasets, and requiring distinct expertise.

Figure 1.

A framework to achieving equity through the elimination of health disparities with adverse drug events (ADEs) by ADE subclass. ADEs comprehensively cover any injury related to pharmacotherapy including therapeutic failure, whether or not the therapy is taken. Adverse drug reactions (ADRs) and access‐related ADEs disproportionately impact groups that have been historically marginalized. Interventions that eliminate the health disparities of ADEs vary by subclass (ADEs relevant to health disparities are within the blue‐shaded area). To address ADR disparities, which occur despite evidence‐based regimens and appropriate administration, precision medicine approaches are employed that identify factors impacting pharmacological drug response. The better our understanding of the diverse factors affecting drug response in ancestrally diverse study populations, the more likely evidence‐based treatment guidelines will improve outcomes for all patient groups. Pharmacogenequity is the state when disparities are no longer observed in risk for ADRs. Pharmacoequity has been eloquently described by Essien et al., ² but briefly can be achieved by policy interventions that address cost and physical access to life‐saving therapies. Both pharmacogenequity and pharmacoequity should be achieved in tandem to address ADE health disparities. This framework is intended to provide a simplified, conceptual overview rather than an exhaustive depiction of all possible nuances (e.g., a proportion of medication errors can lead to health disparities).

Summary

Well‐defined terminology can tangibly advance a field by improving the research itself (e.g., improved hypothesis formulation, study design, cross‐collaboration, and knowledge accumulation) and bringing more attention to it. This can in turn enhance funding opportunities, fuel more research studies, heighten awareness on barriers, and increase the pipeline of future scientists entering that field.

Precision medicine work that falls adjacent to, but not within, the pharmacoequity framework has not been explicitly defined. Pharmacogenequity as a concept addresses this problem. Similar to pharmacoequity, pharmacogenequity also aims to improve equity in health outcomes for pharmacotherapeutic treatment of a disease or condition. It has already shown success in this endeavor as an active area of study or implementation for many scientists and clinicians. Pharmacoequity and pharmacogenequity complement each other. Although more research is necessary to determine the potential synergy in achieving these goals relative to one another, it is certain that both should be achieved in tandem to eliminate adverse drug event‐related health disparities.

FUNDING

Financial support for this work was received from the National Human Genome Research Institute under the National Institutes of Health (R01HG012824). The National Institutes of Health had no role in the conceptualization, writing, or decision to submit this manuscript for publication.

CONFLICTS OF INTEREST

The author declared no competing interests for this work.