Nowadays it is high time for the personalized medicine approach. As a part of this healthcare strategy medics use special testing methods – one called pharmacogenomics (PGX). PGX testing detects how the patient’s genes affect certain medicines’ use.
Testing certain patients’ genes can help doctors in the prediction of a patient having a bad or zero response after taking a drug along with the possibility of side effects. This new approach to customizing medical treatments can change how we deal with managing illnesses and evaluating risk.
Also, PGX generic testing provides a more focused method for picking the correct medicine at the most appropriate dosage level. The patients will feel safer when following the recommended treatment if they have the results of such tests before starting the therapy course. In this article, we will explore the benefits and limitations of PGX testing to understand its boundaries and availability in healthcare facilities.
What Is PGX Testing?
According to the numerous clinical trials the abstracts of which were posted in the research of the National Center of Biotechnology Information, the main concept of pharmacogenomics is to detect and analyze different genes in a human body. The results of PGX testing define how this body will respond to the use of specific medications and pharmacological treatments.
The tested gene variations, called single nucleotide polymorphisms (SNPs), define how the patient’s body absorbs, distributes, processes, and removes from the pharmacological treatments. The major group of genes that play a crucial part in drug metabolism is cytochrome P450 (CYP) enzymes.
These enzymes – especially CYP2D6, CYP2C9, and CYP2C19 – are important for breaking down a variety of medications such as antidepressants, painkillers, heart medications, etc.
The natural differences in genes revealed during PGX tests classify all the people as:
- poor metabolizers;
- intermediate metabolizers;
- extensive metabolizers;
- ultrarapid metabolizers;
The metabolizer category can assist healthcare providers in customizing the pharmacological treatment, for example, to correct the dose of the prescribed medicines to reduce the risks of side effects.
Besides affecting the function of CYP enzymes, genetic factors may predict the body’s response to certain drugs. Particularly, the genes related to drug transporters (e.g., SLCO1B1) and drug targets (e.g., VKORC1) are part of the complex relations between genetics and the medications’ effect in a person’s body.
The goal of the PGX DNA testing method is to detect all these different genetic elements and present the overall analysis of how someone’s body might respond after the use of certain medications.
How Is PGX Testing Done – Specifications
A standard PGX test includes the laboratory analysis of different genetic variations of a tested patient. However, the testing methods may differ in various PGX testing companies. These variations are single nucleotide polymorphisms (SNPs), copy number variations (CNVs), and insertions/deletions.
SNPs, which change one nucleotide at a certain location in the genome, are the most common variations tested during the PGX lab test. CNVs indicate the removed or copied DNA fragments to help healthcare providers define the potential response of a body to certain drugs.
In general, a PGX test analyzes numerous genes responsible for the body’s response to certain chemicals. The usual genes tested are CYP2D6, CYP2C9, CYP2C19, SLCO1B1 and VKORC1. These genes participate in drug metabolism, the transportation or targets of the drug’s components.
PGX Testing Methods
The most common PGX testing methods are:
- Polymerase chain reaction (PCR) is a procedure to increase the number of certain DNA areas;
- Sequencing means detecting the exact order of nucleotides in a DNA example;
- Microarrays are chips with thousands of tiny spots on them. Every spot represents one specific genetic variation and they allow the lab specialist to check a lot of genes and variations at once;
Accuracy of PGX Tests
The most important parameters of PGX tests are sensitivity and specificity which define the accurate rates of the results.
Sensitivity shows how well a test can identify the people who have certain genetic differences. Specificity indicates the accuracy of the identification of such people without these specific changes.
If a test gives incorrect positive results, a healthcare provider may interpret a genetic difference that doesn’t even exist in a patient’s body. Otherwise, the false negative results do not show any gene variations while they actually exist. That is why reputable PGX testing companies strive to minimize such drastic errors through rigorous quality control measures.
The Interpretation of PGX Tests
Understanding and using the outcomes of PGX tests is not that simple. This requires special knowledge in genetics and pharmacology. Normally, the lab presents the results as a report specifying the person’s genotype for every genetic variation tested. Also, the report should include an explanation of how the revealed variation could affect the patient’s response to certain chemicals in drugs.
Applications of PGX Testing
The properly implemented PGX testing services can be useful in many healthcare-related spheres, giving medics and doctors the chance to improve their treatment plans for patients with various diagnoses.
Oncology
PGX testing can significantly improve the chemotherapy process – the results affect the cancer patients’ dose and selection of chemicals. After analyzing the genes related to drug breakdown or transportation of DPYD and TPMT, oncologists can find out which patients are more prone to severe consequences from the use of chemotherapeutic agents like 5-fluorouracil and mercaptopurine.
Mental Health Disorders
The genetic testing of CYP2D6 and CYP2C19, which play a huge role in metabolizing various antidepressants and antipsychotics, can help healthcare providers pick the medications for patients suffering from depression and psychotic disorders. This PGX testing method might boost how well someone reacts to treatment, decrease the chances of side effects, and cut down the time period required to find an effective medicine routine. In such a way, mental health patients can get better healthcare and improved quality of life.
Cardiology
Anticoagulants and antiplatelet medicines like warfarin and clopidogrel are the common medications prescribed to prevent or treat heart disease. However, the changes in genes such as CYP2C9, VKORC1, and CYP2C19 can have a big effect on the efficacy and safety of these medications. After getting the results of the patient’s PGX blood test, cardiologists can improve the pharmacological therapy including anticoagulants and antiplatelet drugs.
In such a way, they can reduce the risks of complications related to internal bleeding and possible heart insults. Also, such tests can help to prevent the possibility of statin-induced myopathy development which is an uncommon yet severe negative reaction among people with heart conditions and certain genetic variations.
Pain Control
In this sphere, the PGX testing methods can assist in picking the right opioid analgesics and their dosage. Certain genes like CYP2D6 and OPRM1 reveal how opioids like codeine and morphine behave in the human body. The proper results of PGX tests can invest in a better pain management therapy for the patient who needs an effective pain control medication with minimal risks of developing an opioid addiction.
Limitations and Challenges of PGX Testing Labs
Even though there are many benefits of PGX testing, healthcare providers should understand the various limits and difficulties that come along with the numerous advantages. The first challenge is the complicated interactions between genes and drugs. Even if PGX tests can offer an overview of genetic variations and predict how a person may respond to medicines, it is very important to understand that other factors besides genetics – like age, kidney and liver function along drug interactions – also have a substantial impact on pharmacological treatment’s effectiveness and safety.
Another challenge is the absence of uniform methods of PGX tests. If you google “PGX testing near me”, you will find out that various U.S. laboratories use different methods. Right now, each PGX lab test analyses diverse genetic variations and the results are delivered in diverse formats. Such an approach leads to confused and uneven reports in different states. That also explains why the use of PGX tests is restricted in certain medical institutions due to insufficient proof and methods.
Also, PGX testing is sometimes considered unethical. When it comes to lab blood tests, the major ethical principle is to preserve the privacy and confidentiality of patient’s data. Especially, the genetic details are highly sensitive and personal to be disclosed in public. The process of getting legal consent from a patient needs to be more thorough. Patients have to understand all the aspects involved during the innovative PGX testing methods. Dealing with these ethical issues is crucial to uphold patient’s trust.
How to Integrate PGX Testing Services into Healthcare Practice?
The integration of PGX tests into regular clinical practice requires the use of a comprehensive strategy tackling the healthcare provision.
The Adherence to Standards
Multiple professional groups, like the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG), have approved the national standards to employ this test and interpret the results for certain medications and gene combinations. These standards are constantly improved and adjusted. And a reputable pharmacogenetics company should adjust their tests as well to prevent any violation of these regulations.
Cost -Effectiveness
The price of the service is another factor to consider by healthcare providers who intend to implement these services in their facilities.
In particular, the PGX testing reimbursement plans are quite essential to consider. Although the average PGX test price has reduced recently because of the significant progress in genotyping technologies, not every clinic and laboratory still can afford to offer these services with cost-effective strategies.
A few large insurance providers are ready to cover the PGX testing cost when it comes to certain medical plans, yet most still see it as a part of the unnecessary services. It is crucial to prove to the majority of insurance providers in the U.S. how PGX testing can be cost-effective. For example, a recent study posted by the National Library of Medicine indicated that PGX tests can actually save costs by cutting down on drug reactions, enhancing medicine efficacy, and preventing pharmacological prescriptions based on the trial-and-error method.
The Use of Electronic Health Records
And last but not least, the implementation of PGX testing requires the use of other modern approaches. One of them is the innovative system of electronic health records (EHR). The digitalization of medical records can be updated in real-time with constant access of certain healthcare providers to the test results. In such a way, patients of clinics and laboratories can be sure that the doctors have a full picture of their diagnosis and tests before deciding on a specific pharmacological treatment plan.
The cooperation among healthcare professionals, lab specialists, and patients is extremely important for the successful integration of PGX testing methods.
Conclusion
PGX testing is a groundbreaking method in modern personalized healthcare services. Such an approach to individual testing can change how medics deal with drug therapy and improve its results for patients.
To experience all the benefits of PGX testing services healthcare providers should correctly integrate these methods into their clinical practice. They need to handle such important issues as following the PGX testing standards, education of the medical staff, ethical matters, and proper communication with a patient during the testing procedure.
If implemented correctly, the PGX testing methods can drastically change the personalized pharmacological treatment, and its effectiveness and predict the better healthcare routine in every individual case of therapy.
