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What is Pharmacogenomics?

Did you know that every year, 1.9 million people are hospitalized as a result of the side effects of prescription drugs? Many drug side effects come about because the medication itself isn't right for the individual's genes. For that reason, pharmacogenomics was invented.

If you've never heard of the term before, you might be wondering, "What is pharmacogenomics exactly?" It is a relatively new field of study that involves researching how genes interact with medications. Through this research, scientists might one day be able to create medications that match a person's individual genome.


Not only is this important for reducing dangerous drug side effects, but it can also improve the effectiveness of the drug itself. It can even influence medication management of certain conditions such as cancer and Alzheimer's disease which have long been notoriously difficult to treat. To learn more about how pharmacogenomics works, keep reading.


What Is Pharmacogenomics?

The collection of all the genes in the human body is known as the genome. Every gene in the body has a particular use. More often than not, it codes for a specific protein.


These proteins can be responsible for various things in the body. They may help digest food or deliver nutrients throughout the blood.


Other genes may be responsible for hair and eye color. Many genes are very helpful to the formation and function of the human body, but some genes can actually be harmful.

For example, there are some dangerous genes such as the BRCA gene which is linked to the development of breast cancer. There are other genes that may be linked to other types of cancer such as hereditary cancers. Today, traditional drugs treat conditions based on a variety of factors, but no traditional drug is able to treat a condition down to the level of the genes.


That's why pharmacogenomics is so important. Pharmacogenomics is also known as precision medicine because it aims to be precise when it comes to treating certain conditions caused by faulty genes. It also aims to not interact with genes in an unhelpful way that might cause side effects due to Gene Drug Interactions (GDIs).


Pharmacogenomic tests often try to identify genes that make up the group of enzymes, cytochrome P450, also known as CYP450. These enzymes are important because they are the primary enzymes that break down drugs in the body. The genes for CYP450 in many people are different from person to person.


For that reason, one person may be able to metabolize a certain drug without any problems. On the other hand, another person may consume the same drug and have horrible side effects. By identifying the gene variations, pharmacogenomics can better treat people.


Pharmacogenomics and Cancer

In this guide to Genomics, you will find that cancer is one of the most important issues that this field of medicine is trying to deal with. Some cancers are hereditary while others may occur later in life due to damage to the DNA. For example, familial adenomatous polyposis (FAP) is an abnormal gene that is passed down from parent to child.


It is a defective version of the gene adenomatous polyposis coli (APC). The defective version predisposes the affected person to develop polyps throughout their large intestine. These polyps have a high likelihood of becoming cancerous later in life.


As a result, many people with this genetic condition often have to have parts of their large intestines removed because they are so riddled with polyps. Hereditary forms of cancer tend to be rarer than acquired cancers. For example, skin cancer is a common type of cancer that people can get when they spend too much time in the sun.


The sun will eventually break down strands of DNA in the skin. This creates thymine dimers which bind the DNA strands in abnormal ways. It may lead to cancer.


Genomics can help with inherited and acquired cancers by first studying the changes in these genes and how they vary from the normal, non-cancerous gene.


While genomics is still in its early stages when it comes to the treatment of cancer, it has made some progress. For example, pharmacogenomics is able to test for thiopurine methyltransferase (TPMT) which is an enzyme that breaks down certain cancer drugs. Those who don't have the TPMT enzyme may experience toxicity as a reaction to the cancer drugs.

By identifying those who are deficient in TPMT, doctors can choose better cancer treatment options for those patients.


Pharmacogenomics and Antidepressants

Antidepressant medications tend to cause many side effects, some of which can be life-threatening. This is unfortunate since more than 280 million people worldwide suffer from depression. There are many types of antidepressants but all of them can cause side effects such as nausea, constipation, insomnia, headaches, fatigue, and even suicide.


People who are already suffering from depression should not have to suffer from the potentially debilitating effects of antidepressants. One of the most common types of antidepressants is selective serotonin reuptake inhibitors or SSRIs. As the name suggests, the drug has a lot to do with how the neurotransmitter serotonin interacts with the brain.


Serotonin is one of the feel-good hormones in the brain. People with depression may have lower levels of serotonin than normal. That's where SSRIs step in.


By blocking the reuptake or absorption of serotonin in the brain, more serotonin can start to build up. The theory is that once enough serotonin builds up to normal levels, the symptoms of depression should start to wane. There are many genes that are responsible for the production and resorption of serotonin.


There are also more genes responsible for interacting with SSRIs. However, not everyone has the genes needed to interact with SSRI medications. Through pharmacogenetic testing, doctors would be able to see which people would not be good candidates for SSRI drugs. But it doesn't stop there.


With this information, researchers would eventually be able to create new antidepressant drugs. These drugs would be able to match the genomes of people with different genes responsible for drug metabolism. By doing this, people who suffer from depression wouldn't struggle so much with finding the right antidepressant.


Instead of dealing with side effects and trying different antidepressants, pharmacogenomics would allow them to find the best medication for their genome after a patient's history failed to help them select the right drug.


Pharmacogenomics and Diabetes

Some people are more prone to developing diabetes than others. Some are even born with diabetes. For example, there is a type of diabetes known as diabetes mellitus.


This condition is characterized by high glucose levels in the blood and urine. As a result, these people often lose weight and are always thirsty. HNF1A is an abnormal gene responsible for making these people sensitive to sulfonylurea. Sulfonylurea is a drug that doctors often give to people with type II diabetes.


Imagine if a doctor gave someone with diabetes mellitus sulfonylurea medication. They would have an extreme adverse reaction. Pharmacogenomics would be able to identify the HNF1A gene.


By doing this, doctors would know to avoid sulfonylurea drugs. Instead, they would be able to use drugs that would better treat the condition. This case is similar to other diabetes types.


By finding out the genes a person has, a doctor can make better decisions. By making better decisions, patients wouldn't have to suffer from drug side effects.

Pharmacogenomics and Alzheimer's

The effectiveness of medications for Alzheimer's disease tends to vary in effectiveness. Some drugs work great for some while not so great for others. Acetylcholinesterase inhibitors are the most common medications for Alzheimer's disease.


These drugs are one of the few drugs that have any effect on this disease. However, only one-third of patients see an improvement. Different responses to medications may be explained by the P450 (CYP) enzymes.


To metabolize acetylcholinesterase inhibitors, one would need these enzymes. Without them, the drugs would not work. As a result, the symptoms of Alzheimer's disease would only worsen.


Pharmacogenomics is essential here. By studying our genes, pharmacogenomics would be able to tell which enzymes we might be missing. If a person is missing some important enzymes, they would need to take another medication.


Or, another medication would need to be developed. Whatever the case, pharmacogenomics can help advance the state of the drug industry. It could provide more options to patients that are unable to metabolize certain drugs.

By finding the right medications, certain conditions like Alzheimer's wouldn't need to get worse. Or, rather, doctors could prolong the number of good years a patient has.


Pharmacogenomics and Cardiology

Asthma is a condition that inflames the airways. This can make it hard to breathe. As a treatment, people usually need to inhale corticosteroids.


The corticosteroids would diminish the inflammation. As a result, the person would be able to breathe again. Asthma may come about for many reasons such as pollen or other allergens.


However, some forms of asthma seem to be genetic. Asthma has a tendency to run in families. It may have to do with the genes that encode the body's inflammation response.

Normally, the body should only mount an immune response to fight a threat such as an infection. However, some people have a hypersensitive immune response. This response may cause asthma.


By learning more about the genes responsible for the immune and inflammation response, doctors would be able to better treat those who suffer from asthma. More than that, doctors could prescribe the right medications. This could save patients a lot of time and money.


Many patients need to hop from one medication to the next. This is because many medications won't work for certain people. Pharmacogenomics would allow patients to get the best treatment on the first try.


Pharmacogenomics and Arthritis

Arthritis is an inflammatory condition that affects the joints. It tends to occur in older people. It may affect the knees, elbows, spine, and fingers, among other joints.


It can be very painful and even debilitating for some people. There are also types of arthritis such as rheumatoid arthritis or RA. This form is actually an autoimmune condition.


Over time, RA can deform the joints in the fingers. It can make it difficult or even impossible for one to use one's hands. Doctors typically use anti-inflammatory drugs to treat this condition.


However, these drugs don't always work. Again, this has to do with the cytochrome P450 enzymes which metabolize drugs. Some people may have abnormal cytochrome P450 enzymes while others may, for the most part, lack them.


If there is a problem with someone's cytochrome P450 enzymes and the doctor doesn't know, the person may experience drug toxicity. In some cases, this can be fatal. In other cases, the toxicity may wreak havoc on bone marrow and the liver.


Pharmacogenomics can make it so doctors never make this mistake. Through pharmacogenomic testing, doctors would be able to check the state of a person's enzymes. This could greatly diminish the occurrences of drug toxicity.


Pharmacogenomics and Pain Management

Millions of people suffer from chronic pain. Rheumatoid arthritis, as mentioned before, is a type of chronic pain. Other people may have pain resulting from accidents or injuries.

Some forms of pain may even result in disability. For some forms of pain, normal pain medications like acetaminophen might not work at all. Treating pain with medication has to do with biomarkers.


Biomarkers are variations in DNA. These variations are important when it comes to how people experience pain relief. One drug may eliminate someone's pain while it might not do anything for someone else's pain.


Using pharmacogenomics is important for analyzing these biomarkers. This way, people who suffer from chronic pain can find relief.


All About Pharmacogenomics

Pharmacogenomics is a relatively new field of medicine, but it is already making leaps and bounds. It is essential to find the best medications for the individual. Without pharmacogenomics, patients may suffer dangerous drug side effects that could even be life-threatening.


To learn more about pharmacogenomic testing, contact us here.

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