Medtronic Irish takeover plans could be affected by changes to US tax rules

Medtronic, the Minnesota- based medical device maker that’s planning to take an Irish tax address, may become one of the biggest losers under rules announced today by the Obama administration.

Among the likely winners is Horizon Pharma, which just last week completed an address change — known as an inversion — from Illinois to low-tax Ireland.

The new Treasury Department rules take effect today, capturing companies like Medtronic that are still in the process of switching nationalities and sparing those that have already finished their transactions.