More than 1,000 of the country's 1,500 pharmacists have given 30 days notice of their intention to withdraw from the Community Drugs Scheme.
Today a 34% cut in payments to pharmacists for providing medicines and advice to patients in the community drugs scheme came into effect.
The Irish Pharmacy Union says the cuts could lead to the loss of up to 5,000 jobs in pharmacies and will undermine patient services.
It has called for urgent talks with Minister for Health Mary Harney.