Minnesota State Sen. Amy Klobuchar has voiced concern about a growing shortage of prescription drugs, including morphine and cisplatin, a widely used cancer drug. According to Klobuchar, 150 drugs are now considered in short supply in the United States -- twice as many as five years ago. As a result, she said, she plans to introduce legislation to speed up the availability of substitutes, including comparable drugs from other countries. In the past few weeks, hospitals and clinics in Minnesota and around the country have had to scramble for adequate supplies of key medications. The shortages have been blamed, in part, on production problems as well as decisions by drug manufacturers to stop making inexpensive generic drugs. In addition, a California plant that manufactures cisplatin was shut down by federal authorities earlier this year because of concerns about bacterial contaminat