WASHINGTON (AP) — Growth in global prescription drug spending will slow to the lowest rate in decades as low-cost generic drugs continue replacing former blockbusters in the U.S. and Europe, where governments face new pressure to reduce health care spending, according to a new forecast.

The projection from data firm IMS Health shows the global prescription drug market growing by 3 to 6 percent over the next four years to $1.2 trillion by 2017. That compares to a growth rate of 5.4 percent in the last four-year period.