What is pharmacogenomics?

Pharmacogenomics is the study of how genes can affect your response to medication and is a branch of personalised medicine. It is a relatively new field that combines pharmacology and genomics to determine prescriptions of drugs and even the dosage that is most likely to work for you. For personalised medicine, you can see a psychiatrist.

Due to genetic makeup, some people’s bodies break down medications too slowly. If the medication builds up in the body, it may cause severe side effects.

For example, gene CYP2D6 makes a protein responsible for breaking down many medications, including the pain killer codeine. When CYP2D6 breaks down codeine, it converts it into another molecule called morphine which relieves pain. Some people have a variant in the gene and this can cause codeine to be less active, this means that the drug may be less effective at relieving pain.

Other people may convert codeine too quickly, causing too much morphine in the body. This means they might be at an increased risk of side effects.

One goal of pharmacogenomics is to figure out if a patient is a poor or rapid metaboliser of drugs and ultimately they determine which drugs are best for you overall.

A gene screening (or pharmacogenomic test), can determine what impact genes such as CYP2D6 (as well as many others) may have on the way your body interacts with certain drugs.
 

What does a pharmacogenomics test involve?

Through a simple saliva test, results are usually ready within two to three weeks. It can indicate to the doctor what drug and dosage to give to a patient and can help avoid side effects.
 

Why is it done?

By having access to your genetic data, your doctor can almost eliminate the trial and error often found in prescribing and shorten the time to find the right medication for that person.

The types of medicine you should take can be predicted as well as which ones you should avoid.

Through pharmacogenomics, you can find out

• whether a medication may be an effective treatment.
• what might be the best dose of medication for you.
• whether you could have serious side effects from a drug.

The goal is to find out the right drug for the right patient at the correct dose.
 

What are the benefits of the test results?

Once your doctor has seen and analysed your test results, they will know precisely what to prescribe and at what dose.

How long are pharmacogenomic test results valid for?

Since your genetic makeup doesn’t change with age, the results will remain relevant, and they can be used whenever you require prescription medicine.
 

How accurate are pharmacogenomics tests?

It may depend on the test, however, a test called PGxOne™ Plus is often used and has displayed 100% sensitivity (true positive detection rate) and 100% specificity (true negative detection rate).
 

Who is responsible for interpreting data from a pharmacogenomics test?

A laboratory interprets the results and would send your doctor a clear, easy to understand report.