How pharmacogenetic (PGx) testing works

Pharmacogenetic (PGx) testing uses DNA tests to understand how certain drugs will affect each person¹. Find out what PGx is and what treatments it could be used for.

What is pharmacogenetic (PGx) testing?

Pharmacogenetic (PGx) testing is a DNA test that may help to identify how your unique genetic makeup may affect your response to drugs¹.

Our individual genetic makeup plays an important role in how we metabolise and respond to drugs. This means that two people could be given the exact same dose of the same drug and have very different reactions. For some people, it can take months of adjustments to get drugs working effectively. PGx may help health care providers personalise your treatment so that you could get the right drug and the right dose.

Benefits of PGx testing

Everyone metabolises different drugs at different rates. This may affect how well certain drugs work for you. For example, if you process a drug too quickly, this may reduce its benefits or effectiveness, and if you process it too slowly, it may increase your risk of side effects.

Pharmacogenetic (PGx) testing may be considered by your GP in some cases to:

• reduce the likelihood of ineffective drugs or doses
• reduce the risk of side effects and long-term health impacts
• potentially save time and money spent on trial-and-error drugs
• determine a suitable dose of certain drugs sooner.

PGx testing doesn’t replace all tests, or all the information that your health care provider already has about you. It’s designed to complement your existing treatment and your provider’s care and expertise.

PGx testing and mental health

Getting the treatment right can be particularly challenging for some mental health conditions. For people who need treatment for mental health conditions, finding the right drug may take a fair bit of trial and error – sometimes months or years of it. And the side effects of these drugs can sometimes make you feel worse rather than better.

If you need to take drugs for a mental health condition, speak to your treating physician about whether PGx testing might help provide a treatment that’s suitable for you, so that you could get the right dose of the right drug.

How can I get a PGx test done?

A PGx test is like other pathology tests. Start by talking to your GP or specialist doctor about whether PGx testing could be appropriate and effective for you and your condition. If it is, they may provide you with a pathology request form to get the process underway with a pathology lab or DNA testing lab.

Traditional clinical genetic testing usually involves taking a blood sample at a pathology collection centre.  Alternatively, you can order an at-home test kit supplied by a provider and collect a cheek swab or saliva sample. Once you receive your report, your doctor will be able to discuss the results with you and make any recommendations on your treatment from there.

Keep in mind that very few pharmacogenomic tests are currently subsidised under the Medicare Benefits Schedule (MBS).