Community pharmacists in Northern Ireland have voted to take industrial action.
The decision was prompted by what they describe as "insurmountable funding pressures" and a "staffing crisis".
More than 123,000 people use their local pharmacy every day, with the service seen as a vital link between patients and GPs.
Health Minister Robin Swann said the vote for industrial action was "regrettable and surprising".
It is not clear what form the industrial action will take or when it will start.
Community Pharmacy Northern Ireland said 98% of its members at a meeting on Monday night voted to take industrial action.
Representatives of 418 pharmacies in Northern Ireland attended the meeting.
The body said community pharmacists have reached "breaking point" and there were major concerns about maintaining a safe and ongoing supply of medicines.
Mr Swann urged Community Pharmacy Northern Ireland to reconsider its plan for industrial action and called on the body to "work with me to develop a sustainable way forward".
"I am very aware of the challenges within community pharmacy, including the need for greater funding certainty," added the health minister.
"I want to assure patients that contingency measures will be developed to minimise the impact of any industrial action."
Gerard Greene, the chief executive of Community Pharmacy Northern Ireland, said: "We have been warning the department for years of this growing crisis.
"The decision to take action is not one reached lightly and we regret that the refusal of the department to address this crisis has brought us to this.
"Our network is at the point where the safe delivery of crucial frontline services for patients could be compromised."
On Monday, the four main health unions in Northern Ireland reached agreement on pay and safe staffing levels with the Department of Health, ending months of strike action.