Pre-Emptive Pharmacogenomics (PPGx)

PGx may be performed in different ways. In the first scenario, a doctor decides to prescribe a certain medication for a patient. He or she then orders a genetic test that is relevant to that medication. The doctor uses the results from the genetic test to decide on the optimal treatment and dose for the patient, in order to maximise drug effectiveness and minimise adverse drug reactions (ADRs). This method, called reactive PGx, can take days, resulting in a delay in treatment. It is also relatively expensive because only one gene is tested at a time.

A Vanderbilt University study of 10,000 people in the U.S. showed that 91% to 96% had a genetic variant that was likely to affect their response to at least one of five commonly used medications that are known to be affected by genetic variants. Another study of 1,000 people at the Mayo Clinic found that 99% had an actionable genetic variant for response to one of five common medications (three of which were the same medications as in the Vanderbilt study).

For this reason, another type of PGx called pre-emptive PGx may be more efficient than reactive PGx. Pre-emptive PGx involves testing for multiple genetic variants that could influence commonly used medications. This testing is carried out before the patient needs these medications. The information is stored in the patient’s electronic health record (EHR). When the patient’s doctor orders one of these medications, the genetic information is immediately available, allowing the doctor to decide on the patient’s treatment there and then. In this way, treatment can start without delay. Pre-emptive PGx also requires fewer tests and is less expensive than reactive PGx.We will initially perform pre-emptive PGx on 1000 patients from several specialty clinics and incorporate the genetic information into the patient’s EHRs. 

Concurrently, our team of doctors and researchers at NUHS will develop local PGx clinical guidelines and provide specific recommended actions (best practice advisories) for selected medications with high clinical impact, and incorporate them as drug alerts into the clinical care system. When one of these medications is prescribed to the patient with pharmacogenetics variants, a corresponding drug alert will be triggered real-time in the system for the prescribing doctors to act upon.

For enquiries, please contact ppgx@nuhs.edu.sg.