The HSE has said it will take "very seriously" any refusal by pharmacists to dispense medicine tomorrow.
Irish Pharmacy Union (IPU) members are meeting in Dublin tomorrow to consider what steps to take in the row over their fees being reduced for dispensing medicines under the community drugs schemes.
A spokeswoman for the IPU told ireland.comthat emergency cover would be put in place to ensure medicines would be available to those who need them. She said signs will be placed on pharmacy doors directing patients to other pharmacies providing cover in the area or giving mobile numbers for patients who need further information.
Speaking on RTÉ radio this morning, Ross Hathaway of the HSE's Corporate Pharmacy Unit said he was "very disappointed" that pharmacists were meeting tomorrow.
"Historically the IPU have met on a Sunday to minimise disruption to the public. There is no reason why they are meeting on a Wednesday," he said.
Mr Hathaway urged people to phone a hotline number - 1850 241850 - if they have difficulties getting prescriptions filled.
Both the IPU and the HSE have claimed disruption to services tomorrow will be minimal.
The dispute centres on the decision by the HSE to reduce the margin paid to pharmaceutical wholesalers, in a move aimed at saving €100 million.
Pharmacists argue they could end up paying more for drugs than they get in State reimbursement. They claim the move will result in 300 outlets going out of business and reduce the level of service to patients.
They have accused the HSE of abusing its position by trying to push through changes to the community drugs scheme without agreement.
The IPU expects as many as 500 pharmacists from across the country to attend tomorrow's meeting.
The Mandate trade union is seeking an urgent meeting with IPU president Michael Guckian following his predictions that there could be 5,000 job losses due to the changes to the drug scheme payments.
The union represents over 3,000 members working in the retail pharmacy sector. Mandate assistant general secretary Gerry Light said he was "extremely concerned" at Mr Guckian's statement.
"Regrettably, it has already become apparent that some employers in the sector are citing the impact of the changes as reasonable grounds in denying our members pay increases. We are requesting an immediate meeting with representatives of the IPU to discuss how the impact on our members can be managed best," he said.