Pharmacogenomics: Understanding drug response and personalized medication


The difference between traditional medicine and precision medicine

Screening methods of Breast Cancer
There are two core approaches used for treating disease in the medical field: traditional medicine and precision medicine. Though both are important, they have significant differences which should be understood to help individuals in making informed decisions.

Traditional medicine at its core follows a one-size-fits-all approach and treats patients with medicine based on "symptoms". Under traditional medicine, doctors or pharmacists use experience to dispense the dosage and type of medicine to alleviate patient symptoms or roots of illnesses. Patients may have to go through continuous testing, drug changes, and dosage adjustments to reduce drug side effects or ineffective medication, all to find a relatively suitable drug treatment. This approach is hence less effective in treating specific patients, and it is more difficult to avoid adverse effects.

Precision medicine, on the other hand, is a major medical trend in recent years. Under precision medicine, pharmacogenetics is used to simultaneously pinpoint the correlation between "symptoms" and "genes". Genetic differences can lead to different drug reactions. Pharmacogenetics can directly rule out treatment options that are not suitable for patients, and suggest to doctors or pharmacists the type and dosage of drugs that are most effective for each patient. Through acknowledging individual genetic differences, precision medicine allows for the personalization of medicine, using the most effective treatment plan to treat the right people at the right time.

Is there a chance that everyone's medication effectiveness and side effects are different?

Everyone has a different drug response which can be influenced by external or internal factors. Examples of external factors include whether individuals are taking other drugs at the same time, which may lead to drug interactions; individuals may also experience other drug reactions after eating foods and drinks which influence the function of drugs taken. On the other hand, internal, personal factors that affect drug response can consist of height, weight, age, other diseases which affect body function (such as kidney disease, liver disease), and even genes. The above factors will affect each person's response to drugs, and the type and dosage of drugs prescribed needs to account for individual differences to maximize effectiveness.

In particular, gene mutations can change the expression and/or function of drug metabolizing enzymes, transport proteins, and drug targets, leading to differences in drug response. Simply put, genetic differences affect an individual's metabolism. For those with fast metabolism, the body quickly metabolizes the drug; this may lead to reduced drug efficacy as it is processed too quickly. Conversely, for individuals with slow metabolism, drugs are excreted too slowly; this may cause toxins to accumulate in the body, causing side effects or adverse reactions.

Trends in personalized medicine: understanding genetic testing for drug response

Through drug genetic testing, it is possible to check whether the patient has genetic mutations that affect drug response, which can help improve the efficacy of medication, save the cost of medication changes, avoid adverse reactions, and reduce side effects.

Codex’s drug genetic testing is followed by a report analysis according to the latest pharmacogenetics guidelines, including the Clinical Pharmacogenetics Implementation Association (CPIC), the Dutch Pharmacogenetics Working Group (DPWG), the U.S. Food and Drug Administration (FDA), and European Public Assessment Reports (EPARs) of the European Medicines Agency (EMA). With genetic analysis supported by scientific research, Codex provides medication guidelines for patients, such as recommended drug changes or drug dosage adjustments.

Medication Instructions

Ultimately, drug responses are very complex and can be influenced by many factors, including genetics. After obtaining a drug genetic test report, you must find feasible medication plans under the guidance of a doctor or pharmacist. Please do not adjust the drug dosage or stop the drug yourself.