Pfizer Inc , which plans a $160-billion merger with Ireland-based Allergan Plc to slash its U.S. tax bill, on Jan. 1 raised U.S. prices for more than 100 of its drugs, some by as much as 20 percent, according to statistics compiled by global information services company Wolters Kluwer. Company spokesman Steven Danehy could not immediately confirm the remaining price increases, which were compiled by a unit of Wolters Kluwer Health and published in a research note by UBS Securities.