Pharmacogenomics… huh???

Your genetics and personalised medicine

You may have heard something about personalised medicine and the tongue twister – pharmacogenomics. But what is it? And might it be beneficial? We take a quick look at this exciting field of research and things to consider before diving in.

Let’s start with the word… it’s a mouthful!

The word “pharmacogenomics” is a combination of pharmacology and genomics:

• Pharmacology is the study of the uses and effects of medicines.
• Genomics is the study of all of a person’s genes (their genome), including how genes interact with each other and with your environment.

A (very) little bit of biology 101.

Almost all the cells in your body contain DNA. DNA is the genetic information that helps make people who they are.

DNA is a double helix. You’re probably familiar with the image – it’s shown on practically every crime or detective show. 😉 It looks like a twisted ladder.

Four different chemicals (nucleotides) pair up to make the ladder’s rungs.

Genes are stretches of DNA. They can be long or short. You inherit your genes from your parents – one copy of each gene from each parent. They contain the instructions to build your body and make you uniquely ‘you’.

Where drugs come into the story.

Your genetic makeup affects the way you respond to medicines.

It can affect whether a medicine is effective, whether it has no effect or whether you have a bad reaction or side effect. It can also affect the dosage you may need. For example, some people absorb medicines too quickly, meaning they need a higher dose to experience any benefit; others process them too slowly, leading to side effects.

Knowing this information about your genes has the potential to help your doctor provide more personalised medicine and a more effective treatment plan.

So how do you know how your genes will react to medicines? You can take a test.

Pharmacogenomic tests are available via some GPs and pharmacists and through direct‐to‐consumer services. They’re generally not covered by Medicare, so you’ll have to pay the total cost of about $150-200.

These tests usually require a cheek swab, salvia sample or blood sample. The sample is sent to be analysed, and a report is provided. If you have gone through your doctor or pharmacist, they’ll explain the results.

Before you jump.

Before jumping on board and spending your hard-earned dollars on a test, there are some things to consider.

• Do you need another test? Many people with chronic conditions already have lots of routine tests to manage their condition. This is not only costly but time-consuming. So ask yourself, “Am I experiencing significant problems with my medicines? And does this test have the potential to provide real benefit?” If so, talk with your doctor. It may be alternative medicines or treatments are an option. Or it might be that your doctor thinks a pharmacogenomic test will help. But first, have the conversation. And read Choosing Wisely Australia’s 5 questions to ask your doctor or other healthcare provider before you get any test, treatment, or procedure.
• The cost. It’s not covered by Medicare, so you’ll have to pay for it yourself.
• Pharmacogenomic tests aren’t available for all medicines. And not all genes and gene variants are tested. International guidelines have so far identified about 15 genes for which testing can inform the prescribing of 30 different medications with good evidence of clinical benefit.
• Not all GPs or pharmacists have the experience or training to understand how to best use these tests and understand the results.
• Your genes aren’t the only player in this game. It’s much more complicated, and many other factors affect how your body reacts to medicines. They include your general overall health, age, other medicines and supplements you’re taking, body size, inflammation, and kidney or liver problems. Your genetics are just one part of the puzzle.
• Safety of your information. Many direct-to-consumer companies offering these tests are overseas, even if the initial delivery address is within Australia. Australian law protects your privacy rights for services provided in Australia, but these protections don’t apply to overseas services. So ask questions about the company – where’s it located, where’s your data stored, who has access to it.

Pharmacogenomics in practice.

We’ve just touched on the briefest of info about pharmacogenomics, so for more comprehensive information about pharmacogenomics in practice in the real world, read this excellent fact sheet from the NSW Government Centre for Genetics Education.

Finally.

The field of pharmacogenomics is growing, and it’s an exciting new world. But you also need to weigh up whether this is something that will benefit you now.

Take the time to do your research, ask questions, and talk with your doctor. These tests aren’t going anywhere. In fact, they’ll likely become more comprehensive and more mainstream as time goes on.

Contact our free national Help Line

Call our nurses if you have questions about managing your pain, musculoskeletal condition, treatment options, mental health issues, telehealth, or accessing services. They’re available weekdays between 9am-5pm on 1800 263 265, email (helpline@msk.org.au) or via Messenger.

More to explore

• Cells and DNA
  MedlinePlus
• Genetic testing and genomics in medicine 2020: Position statement
  Australian Medical Association
• Human gene and disease associations for clinical‐genomics and precision medicine research
  Clinical and Translational Medicine 2020; 10(1), doi: 10.1002/ctm2.28.
• Pharmacogenetic tests
  MedlinePlus
• Pharmacogenetics and pharmacogenomics
  NSW Government Centre for Genetics Education
• Pharmacogenomics in the era of personalised medicine
  Medical Journal of Australia 2022; 217 (10), doi.org/10.5694/mja2.51759.
• Pharmacogenomics: What does it mean for your health?
  Centers for Disease Control and Prevention
• The quest for the era of personalised medicine
  BBC, 2023
• Why prescription drugs can work differently for different people
  The Conversation, 2021
• yourgenome

References

1. A brief guide to genomics, National Human Genome Research Institute
2. Pharmacogenomics in general practice: The time has come. Australian Journal of General Practice 2019; 48