A new medicines management programme could save patients up to €400 a year for each drug they are prescribed.
Dr Michael Barry of the National Centre of Pharmacoeconomics said the programme will be launched next week.
Patients will notice a difference within the next month.
Speaking on RTÉ's Morning Ireland, Dr Barry said: "I feel we will certainly get the buy-in or cooperation from our colleagues up and down the country and for patients it could make a real difference."
He said: "If you are prescribed a lower-cost medication it could save you up to €300 or €400 per drug per year."
Dr Barry said the two areas they will be prioritising are cholesterol-lowering medications and anti-ulcer drugs.
The Government had been encouraged to introduce a new system for prescribing generic drugs as part of the EU-IMF bailout.
A newspaper report over the weekend said that Ireland pays 24 times more for generic drugs than the National Health Service pays in the UK.
Dr Barry said it had not been possible to negotiate a reduction in the price of generic drugs with the manufacturers.
He said: "It isn't right and it's very difficult to defend this situation. We haven't had an effective generic drugs market in this country for many years.
"We all know the price of generic drugs should be between 50% and 90% below the current proprietary drug price. So, it's impossible to defend this."
However, he said a new reference pricing structure, which is part of the Health Bill 2012, will see a reduction in costs.