Merck & Co, the second-biggest US drugmaker by sales, will is to let go of 8,500 workers and revamp its research and development after seeing new medicines delayed by US regulators.
Merck, which is based in New Jersey in the United States, employs around 2,000 people in Ireland under the MSD brand.
There are no details on the geographical breakdown of the job cuts announced today.
In March MSD announced that it would close its plant in Rathdrum, Co Wicklow by 2015 with the loss of 280 jobs.
That was part of an earlier restructuring in which Merck announced the loss of 7,500 jobs worldwide.
The combined firings equals about 20% of the global workforce, and will cut across almost the entirety of Merck, including R&D, sales and management.
The overhaul, to save $1 billion next year, is part of a new strategy being set by Chief Executive Officer Ken Frazier and R&D chief Roger Perlmutter, who was hired in April to replace Peter Kim.
Under Kim, experimental drugs in cardiovascular, surgery, and osteoporosis encountered development setbacks while rival drugmakers were able to get new products to market.
"While these actions are essential to ensure that Merck can continue to fulfill its mission into the future, they are nevertheless difficult decisions," Frazier said in the statement.
The company said it will place more emphasis on developing drugs with the most sales potential, as well as putting more focus on the world's biggest economies, including the US, Europe, China, Japan, Brazil and Russia.
