¶¶Òõ¾«Æ·

PRECISION medicine represents a fundamental shift in how we think about health care. Rather than relying solely on generalised treatment protocols, it incorporates individual genetic, environmental and lifestyle factors to deliver more accurate and effective interventions. At its core, precision medicine seeks to avoid the pitfalls of trial-and-error prescribing by guiding doctors to recommend the right drug, at the right dose, for the right person — potentially reducing adverse effects, unnecessary medication use and the financial burden of inappropriate treatments.

Traditional medicine, by contrast, often follows a ‘one-size-fits-all’ model. Treatment decisions are typically based on generalised clinical guidelines derived from population averages. While effective in many cases, this approach may not work equally well for everyone due to inter-individual differences in genetic makeup, metabolism, or how diseases manifest. Precision medicine, sometimes interchangeably referred to as personalised medicine, seeks to overcome these limitations by tailoring care to the unique biological and physiological traits of each patient.

Ìý

Why DNA mattersÌý

GENES are the carriers of human heredity — long sequences of deoxyribonucleic acid (DNA) housed within the nuclei of our cells. Passed from parents to children, these genes govern a wide array of individual traits, including physical attributes such as height and eye colour, as well as predispositions to certain diseases. However, DNA replication is not always flawless. Small variations in the genetic code — known as mutations or polymorphisms — occur naturally. Although these changes account for only about 0.01 per cent of our DNA, they contribute to the vast diversity observed among individuals, including differences in how we respond to medications.

It is here that ‘pharmacogenetics’, a key pillar of precision medicine, plays a vital role. This branch of science studies how specific genetic variants affect a person’s response to drugs. By understanding these differences, clinicians can begin to predict how a patient will metabolise and react to certain medications.

Ìý

Pharmacogenetics in action

WHEN a person takes a drug, their body must absorb, distribute, metabolise and eliminate it — processes influenced by genetic variations. Some individuals metabolise drugs too quickly, reducing their efficacy, while others metabolise them too slowly, increasing the risk of side effects or toxicity. These variations are typically categorised into metabolic types such as ‘poor’, ‘intermediate’, ‘normal’, or ‘ultra-rapid’ metabolisers.

Pharmacogenetic testing can help identify these differences. Through a simple genetic analysis, often requiring only a cheek swab or saliva sample, clinicians can determine how a patient is likely to process specific medications. This information allows healthcare providers to adjust drug choices and dosages accordingly.

International guidelines from respected bodies such as the Clinical Pharmacogenetics Implementation Consortiu, the Dutch Pharmacogenetics Working Group, and the US Food and Drug Administration offer evidence-based recommendations on drug-gene interactions. Public resources like ‘PharmGKB’ serve as repositories for these guidelines, facilitating their integration into clinical practice.

Ìý

Road Ahead

PHARMACOGENETICS is not a distant concept — it is already being applied in several clinical settings. One notable example comes from Canada, where researchers have developed an evidence-based pharmacogenetic testing programme to support mental health treatment in children and adolescents. More than 2,000 patients with conditions such as depression, anxiety, autism spectrum disorders and ADHD have been treated using this approach. The findings suggest that pharmacogenetic guidance can reduce the reliance on guesswork in prescribing, improving outcomes and reducing both side effects and financial costs for families.

Yet despite these promising developments, significant challenges remain. Implementing pharmacogenetic testing widely — especially in developing countries like Bangladesh — requires infrastructure, trained personnel, public awareness and policy support. The cost of testing, though decreasing, may still be prohibitive for some public health systems without subsidisation or insurance coverage. Furthermore, healthcare providers must be adequately trained to interpret genetic test results and incorporate them into routine care, a process that involves ongoing education and robust clinical decision-support tools.

Ìý

Ethical, social considerations

THE use of genetic information in healthcare also raises ethical concerns. Issues of data privacy, informed consent, potential discrimination and unequal access to technology must be addressed through clear regulatory frameworks. While genetic data can offer life-saving insights, it is crucial to ensure that this information is used responsibly and that patients retain autonomy over how their genetic material is handled and stored.

Moreover, while precision medicine holds great promise, it must not eclipse broader systemic issues in healthcare such as access, affordability and equity. There is a risk that these advancements could primarily benefit urban, well-resourced hospitals while leaving rural and underserved populations behind — thus exacerbating existing health disparities.

Ìý

Strategic opportunity

IN A country like Bangladesh, where public health systems face high demand and limited resources, precision medicine could offer a long-term, cost-effective strategy for improving outcomes in complex diseases such as cancer, diabetes, cardiovascular conditions and mental health disorders. But for this to happen, there must be coordinated efforts involving government policy, investment in laboratory capacity, medical education reform and public-private partnerships.

Precision medicine is not a magic bullet — but it is a powerful tool. When used alongside broader reforms in public health and healthcare delivery, it has the potential to make treatment more targeted, more effective and more humane. In this new era of medicine, embracing science that respects individual difference might just be our best path towards equitable care.

Ìý

Sarker M Shaheen is a neurogenetics and precision medicine researcher.