Dr Latha Palaniappian said, “Pharmacogenomics takes the guesswork out of prescribing."
"Wouldn’t it be wonderful if we had pharmacogenomic testing at birth so we could have a better understanding of how each person will respond to pain medication and anaesthetics, for example?”
She spoke about how precision prescribing is already used in the USA for anxiety and depression medications. She said that this particular group of drugs can take up to six weeks to work (or not work) and many patients have to try several different drugs before they find one that suits them.
“There is increased adherence and better clinical relief if patients find a medication that works a lot faster,” she said.
In the USA, Professor Palaniappian said that pharmacogenomic testing is available for around USD$1200, including a consultation, but that in large trials, around 90% of people received around four ‘actionable recommendations’.
She said that if precision prescribing was implemented nationally, it would save the Government around USD$4000 per patient, in both in-patient and out-patient settings as people wouldn’t be prescribed drugs that have no chance of working for that person’s phenotype.
“The PBS (Pharmaceutical Benefit Scheme) will approve a drug if it works for 90% of patients but what happens to the 5% on either end of that bell curve?” said Professor Palaniappian.
She used examples of people who don’t respond to codeine, as well as people who have low, medium and high sensitivity to one of the world’s most popular drugs: caffeine.
“You know how some people can have a coffee before bed and go straight to sleep, while another person has a coffee at midday and it makes them jittery for the rest of the day? That’s the expression of their unique genotype. We can predict that with pharmacogenomics,” she said.
Professor Palaniappian pointed out that standard genomics is failing on diversity, with most studies looking at cohorts of patients with European ancestry. She said that in a country like Australia with high Asian ancestry numbers, as well as Aboriginal peoples, the sampling needs to be much broader to be meaningful and genuinely reflective of the population.
Professor Palaniappian’s dream? For precision prescribing to be available to everyone.
“It’s clinically effective, cost-effective and can be reimbursable through Medicare,” she said.
