Northern Ireland's health service could save millions of pounds if doctors opted for low-cost generic drugs over expensive brand names, a report has said.
The cost of prescribing medication per head of population is higher here than anywhere else in the UK.
A report by an Assembly spending watchdog has concluded that significant savings could be made.
The Public Accounts Committee said one option was to use generic drugs which are as effective but far less expensive than brand names. It found GPs tend to prescribe more expensive versions of drugs for some common diseases compared to their counterparts elsewhere in the UK.
The report cited how the over-use of pregabalin, an anti-anxiety drug, cost more than £18m in a two-year period.
Today's report also found:
• Prescribing costs have risen in Northern Ireland since 2007, even though they have fallen in every other part of the UK;
• Costs also vary widely between GP practices, with researchers finding a 100% difference between some;
• If we matched Wales' prescribing costs, around £73m could have been saved in a single year;
• A dispute over the payment of pharmacists for drugs cost the taxpayer £46m.
PAC chair Michaela Boyle said: "The committee acknowledges the health service has made savings as it has encouraged the prescribing of lower cost generic drugs.
"However, we believe that significant further saving could be made if the lowest cost versions of generic drugs were prescribed."
Primary care prescribing currently costs £460m a year - around 10% of all health and social care spending. The volume of items prescribed has risen over the last seven years.
The PAC acknowledged GP practices have achieved savings over the last four years, due to a substantial increase in prescribing lower cost, generic drugs.
However, committee members said there was scope to make "significant" further savings.
The report said a comparison of prescribing costs per head of population across the UK suggests that if our costs had been in line with those in Wales in 2013, overall costs could have been sliced by £73m.
The Audit Office, which reported on this issue last November, found that reducing prescribing levels of pregabalin, the most frequently dispensed drug in Northern Ireland, to those elsewhere in the UK would have released £18.2m in 2012 and 2013.
The report urges the department, HSB Board and pharmaceutical contractors to reach agreement on the issue.
"Prescribing costs here are not in line with our counterparts. Given that we are the only UK jurisdiction that has incurred higher costs per head in 2013 than 2007, the committee concludes we have been much slower in achieving savings. This money could have been better used elsewhere."
PAC chair Michaela Boyle