Pharmacogenomics: a new approach to personalized treatment

• Individuals respond differently to medications depending on their genetics, as well as the type and dosage of the drug. After taking medication, genes influence processes such as drug response, absorption and metabolism.
• Pharmacogenomics studies the relationship between human genes and medications, supporting precision medicine by improving treatment effectiveness, predicting drug response, guiding appropriate drug and dosage selection, and helping prevent adverse drug reactions.
• Pharmacogenomic testing can be performed from age 20 and above using a cheek swab or blood test. The results help doctors make more precise treatment decisions.

Through advances in human genome research, our understanding of genes associated with disease risk has expanded. This knowledge directly benefits medical treatment and enables the development of more targeted therapies based on each individual’s genetic profile.
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Pharmacogenomics is a field of genetics that focuses on the relationship between human genes and medications. It supports precision medicine by improving treatment effectiveness, predicting drug response, guiding appropriate drug and dosage selection, and helping prevent adverse drug reactions.

When a drug enters the body, it undergoes multiple processes. Each individual responds differently to medications depending on their genetics, as well as the type and dosage of the drug. After administration, the body must distribute and metabolize the drug. Our genes influence several steps in these processes, which in turn affect how the body responds to medication, as follows:

• Some drugs need to bind to proteins on the cell surface, known as receptors, in order to function properly. Genes determine the type and number of these receptors, which can influence drug response. As a result, each individual may require different types and doses of medication.
• Drug absorption: some medications must be transported into tissues and cells where they exert their effects. Genes influence how much or how little a drug is absorbed, with reduced absorption potentially leading to decreased effectiveness. Genes also affect how quickly drugs are eliminated from the body. If a drug is cleared too quickly, its effectiveness may be reduced or fail to achieve the desired therapeutic effect.
• Drug metabolism: genes can affect how quickly the body breaks down medications. Rapid metabolism may lead to faster elimination, requiring higher doses or alternative medications. Slow metabolism may require lower doses to be administered.
• Targeted drug development: pharmacogenomics enables the development of therapies that target specific problems rather than merely treating symptoms. Some diseases are caused by specific gene mutations, and the same gene may have different types of mutations with varying effects. Certain mutations may result in abnormal protein function or complete absence of protein production. Some medications are designed to target these mutations precisely, improving treatment outcomes.

Pharmacogenomics tests are part of precision medicine, with the aim of tailoring treatment to each individual by using genetic code data to understand drug response. This supports appropriate drug selection, dosage adjustment, and safer use of each medication.

Pharmacogenomic testing can be performed from age 20 and above using a cheek swab or blood test. The results provide important information that helps doctors make more appropriate and personalized treatment decisions.

Advances in medical innovation are increasingly focused on more precise diagnosis and treatment tailored to specific diseases. This approach emphasizes effective treatment outcomes while reducing adverse effects from medications.
Pharmacogenomics in current medical practice can be divided into two main types:

• Drug hypersensitivity genes: testing for drug hypersensitivity genes helps prevent severe, potentially life-threatening reactions. For example, if a certain high-risk gene is detected, doctors may avoid prescribing allopurinol for gout to prevent severe hypersensitivity reactions.
• Dose optimization: genetic testing is used to evaluate various metabolic enzymes in the body to guide pharmacotherapy. This helps determine the most appropriate dosage for each individual, maximizing treatment effectiveness while minimizing side effects. It represents a significant advancement toward precision medicine.

Although medication selection and dosing are traditionally based on clinical studies in large populations, genetic differences among individuals can lead to varied responses to the same drug. Applying pharmacogenomic knowledge allows for more precise and targeted decision-making, helping achieve treatment goals more effectively while minimizing adverse effects.

Currently, pharmacogenomic testing can be applied to more than 500 medications, and that number continues to grow. It covers a wide range of drug groups, including anticoagulants, lipid-lowering agents, pain relievers, sleep medications, psychotropic medications and antiepileptics, as well as medications used to treat cancer, cardiovascular disease, infections, gastrointestinal ulcers and various allergies.

At the Samitivej Genomic and Lifestyle Wellness Center in Bangkok, Thailand, we bring the future of precision medicine directly to you. Our clinical genetics team uses advanced pharmacogenomic testing and personalized genetic counseling to ensure your medications are safe, highly effective, and tailored specifically to your DNA profile. Whether optimizing daily treatments or preventing severe adverse drug reactions, contact our center at Samitivej Sukhumvit Hospital today to take control of your long-term health.