Frequently Asked Questions - Pharmacogenomics

Pharmacogenomics is the study of how genes affect a person's response to drugs. This relatively new field combines pharmacology (the science of drugs) and genomics (the study of genes and their functions) to develop effective, safe medications and dosage that will be tailored to a person's genetic makeup.

Traditionally the drugs have been developed with the assumption that each drug works the same in all individuals. But recent genomics research has proved that “one-drug-does-not work for all”. With more understanding and research it is now possible to personalize drugs for an individual.

Depending upon your genetic make-up some individuals will respond normally to drugs or respond faster or demonstrate slow response. Yet other individuals demonstrate side effects and adverse reactions to the same drug. Based on genetic information doctors can prescribe “right drug” or “right dosage” to the patient.

Studies have shown that Pharmacogenomics testing can save time, money and improve quality of healthcare. So one can be assured that doctors are not using trial and error approach. Patients can benefit immensely by choosing the “best fit” drug from the beginning of the therapy.

Doctors use pharmacogenomics testing to choose the right drug or right dosage of the drug for patients.

Drugs and dosages are usually determined based on patient’s age, gender, weight, blood parameters, liver/kidney function. But genomics research in last few decades has demonstrated that the individual’s genetic make-up also plays an important part in drug metabolism within the body. Some people can absorb or metabolise drugs quickly others take time. Pharmacogenomics helps us understand whether the drug will work or the dosage needs to change.

Applications in Cardiovascular Diseases:

Clopidogrel is an anti-platelet drug used for avoiding blot clots in the blood vessels of patients suffering myocardial infarction, stroke or vascular diseases. Around 40% of the ASIAN POPULATION is not able to metabolise the drug properly or are POOR metabolizers of Clopidogrel. Studies have proved that the occurrence of adverse event (Myocardial Infarction and Restenosis) within a year is increased by 2-3 folds in the patients who are poor metabolizer of Clopidogrel. Hence it is highly beneficial to patients who have undergone angioplasty or suffering from Acute Coronary Syndrome that they get Clopidogrel response pharmacogenomic test done. The outcome of this test helps to DECIDE whether the patient can be put on Clopidogrel or needs to be shifted to other drugs such as Prasugrel or Ticagrelor and hence avoid costly intervention later on.

Statins, the most widely prescribed drugs worldwide, help prevent cardiovascular disease by reducing the level of bad cholesterol in the bloodstream. While statins work well for many patients, responses are highly variable and doctors must adjust the dosage for each person. Research has shown that genetic changes in genes involved in metabolism of statins contribute to the variable response among individuals. Using results of genetic tests, doctors are able to prescribe the right dose from the beginning and more quickly reduce their patients’ risk of adverse events such as muscle pains, cramps and possibly avoid dangerous cardiovascular events such as heart attack and stroke.

Applications in Cancer:

Pharmacogenomics testing is important in choosing the right drug in cancer treatment. Cancers are primarily genetic diseases and affect different organs such as lungs, breasts, ovaries, stomach, mouth among others. Each tumour formed in genetically different from others and specific genes in the tumour DNA decide response to a particular drug. For example, Anti-EGFR Tyrosine Kinase Inhibitors such as Geftinib/Imatinib used to treat lung cancers show positive effects in patients only when certain mutations occur in their EGFR gene. Similarly, the breast cancer drug Herceptin is only effective when the tumor cells have accumulated extra copies of the HER2 gene and have high levels of the protein this gene encodes on their surfaces.

There are many other applications of pharmacogenomics testing in Psychiatry, Organ transplant, Pain management, HIV and other diseases.

Individual’s genetic information can be misused in various ways such as social discrimination or health insurance denial. India has no law to protect individual’s health or genetic information. CromDx follows the guidelines mooted under (HIPAA) Health Insurance Portability and Accountability Act, USA and other genetic testing guidelines to protect the individual’s health data. We use software systems to keep records and anonymize patient details. The report is provided to your healthcare practitioner only.

All humans share 99.9% same genetic material i.e DNA. Only 0.1% difference in DNA set us apart in terms of skin color, hair color, physical traits or carrying risks of certain diseases. These variations or differences in our genes are called polymorphisms or mutations. Some mutations in certain genes may lead to diseases and yet other mutations in specific genes affect drugs metabolism.

Pharmacogenomic tests identify the mutations in genes that are associated with variable response to a drug. The test is able to determine whether a patient is normal, intermediate or poor responder to a drug.

CromDx offers a comprehensive test portfolio in Cardiovascular, Oncology and organ transplant areas.

Please check the individual test descriptions here.

You can get their tests done through your registered medical practioner or Doctor. Based on your medical condition and medications, your doctor can prescribe a pharmacogenomics test. You can then contact CromDx at following contact information

You should contact CromDx sales/sample collection agent to set up appointment for collection in your city. In places where, direct collection is not possible CromDx can train your Physician or Physician’s assistant to collect your sample. Most of the time we request your saliva sample using a cheek swab (Please see sample instructions here).

You have to fill the test requisition form and authorise your consent. Your sample can be picked up from your address by a courier. The test results shall be made available to you and your Doctor. Your doctor shall discuss the report in your next appointment.

An adverse drug reaction (ADR) is an injury caused by taking a medication. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs. There is a lack of proper system to capture and report ADRs in India but in USA over 2 million ADRs are reported each year. ADRs result in 1,00,00 deaths yearly in USA alone and is fourth leading cause of death ahead of AIDS, accidents and automobile deaths (The institute of Medicine, Press 2000). That’s why it is important to know what is the best drug available for treating a patient using pharmacogenomics testing.