The Irish Pharmacy Union has warned that up to 5,000 jobs are at risk because of Government plans to cut payments to pharmacists by more than €130m.
The Department of Health says the action is due to a rapid escalation of costs.
The State paid out €1.68bn in 2008 for drugs and medicines dispensed under community drugs schemes, such as the Medical Card Scheme.
It is estimated that pharmacists would have been paid €550m this year.
But the new measures will reduce that bill to €418m.
The new measures will see the retail and wholesale mark-ups reduced.
Dispensing fees will be increased but paid on a sliding scale.
The Department of Health says the measures will reduce pharmacists payments to 2006 levels.
The IPU says it is looking for an urgent meeting with Minister for Health Mary Harney.
It says it will also consult with its members about the measures, which are due to come into effect on 1 July.
