PARSIPPANY, N.J. (AP) -- U.S. spending on prescription drugs was nearly flat in 2011 at $320 billion. It was held down by senior citizens and others reducing use of medicines and other health care and by greater use of cheaper generic pills.

Last year spending on prescription drugs rose just 0.5 percent, according to data firm IMS Health. The volume of prescriptions filled fell about 1 percent.

That continues a trend of restrained spending that began in 2007. Before then, IMS generally reported annual spending increases of several percent.

The company says it appears patients are still rationing their health care, with visits to doctors and hospital admissions also down. But emergency room visits jumped, a sign some people aren't seeking care until they are very sick.