A pharmacogenetics pilot supported by pharmacists working within general practice has resulted in medicines changes for 25% of participating patients so far, Royal Pharmaceutical Society (RPS) conference attendees heard last week.

Jessica Keen, pharmacy lead at the NHS North West Genomic Medicines Service Alliance, shared an update on the NHS England-funded Pharmacogenetics Roll Out – Gauging Response to Service (PROGRESS) study which has been running in the North West of England since June.

The pharmacogenetics service in primary care would test a patient to understand genetic variations that could affect how they metabolise medication, and then suggest the most appropriate medicine that they would be most likely to respond to, Ms Keen explained to RPS delegates.

She said this could both improve the effectiveness of medications and prevent avoidable adverse drug reactions, which can have 'a huge impact' on the health system, patients and their families.

How could pharmacogenetics be used in primary care?

The study is designed to understand how pharmacogenetics might work operationally in primary care, including how patients want to interact with their results, Ms Keen said.

As part of the study, some patients being initiated on new antidepressants, statins, PPIs, opiates, codeine or tramadol have been offered the chance to receive pharmacogenetic testing in primary care.

She said that patients were 'overwhelmingly' choosing to give a saliva sample rather than a blood sample, although both options were available.

The sample would then be tested in a laboratory and returned to general practice within a week, where pharmacists were able to view the results.

So far, this has been done through a platform called Geno, but Ms Keen said work was taking place on an 'integrated solution' so that the results would be visible within the practice IT system, such as EMIS or System One.

'Then at that point, based on the guidance, the responsible clinician will issue the prescription to the patient using the information that they've got about the patient, as well as the pharmacogenetic guidelines,' Ms Keen said.

A colour-coded system is used, displaying as red for patients who have an altered metabolism, alongside possible alternative options and guidance about why an alternative medicine was being recommended.

'You can weigh that up amongst the other alternatives, the other contraindications or cautions that a patient might have that are not informed by pharmacogenetics,' Ms Keen told pharmacist delegates at the conference on Friday.

And she said that the Specialist Pharmacy Service (SPS) was also working on 'additional medicine information support for patients where there are more complicated queries'.

She told RPS conference delegates that of the 400 patients who had been recruited so far, just two had phoned up to ask for additional information on their results.

'This tells us that perhaps people are well able to understand the guidance in the format that we're returning it,' Ms Keen said.

Prescribing changes had been made in around 25% of patients, she noted, while in three-quarters no change was recommended.

'What we also are seeing is that actually the GPs and pharmacists, when they get these results, are primarily sticking to the guidelines,' she added.

'There are reasonable reasons why sometimes that's not appropriate, because of other cautions, contraindications, or perhaps a patient already started on a medicine, and they feel that they are getting benefit when the guidance might have said they might be less likely to. So, we're seeing that there are occasions where [the guidance might not be followed] but by and large, people are sticking to the guidance.'

Recruitment for the study is continuing and it is now expanding across England, with practices in Hampshire and Cambridgeshire having recently joined, Ms Keen added.

What could pharmacogenetics look like in community pharmacy? The Pharmacist spoke to Dr Tim Rendell to find out.