EDINA (AP) -- U.S. Sen. Amy Klobuchar says she plans to introduce legislation to speed up the availability of substitutes for certain vital prescription drugs that are growing scarce.

She says that 150 drugs are now considered in short supply in the United States, twice as many as five years ago, including some widely-used cancer drugs.

The shortages have been partly blamed on production problems and decision by drug makers to stop producing inexpensive generic drugs.

The Minnesota Democrat says at a news conference Wednesday that she plans to introduce a bill early next year that would require manufacturers to warn the Food and Drug Administration of impending shortages.

The bill would also ease access to similar drugs from Canada and other countries.

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