The findings of an analysis published in the May issue of Health Affairs show that drugs vital to emergency care are increasingly short in supply, despite a 2012 law that allowed the Food and Drug Administration to respond to drug shortages.

The analysis looked at drug-shortage data compiled between 2001 and 2014 from the University of Utah's Drug Information Service. The service includes all confirmed national drug shortages.

During the 13-year span, there were 1,798 drug shortages. Of those, 601 fell within the general scope of emergency medicine. Of the 601 shortages, 321 (53 percent) were drugs routinely used during life-saving interventions or for treating high-acuity conditions. Ten percent of the drugs for life-saving interventions had no available substitute.

Seventy percent of the drugs that were scarce were injectable drugs. Since emergency medicine doctors rely on these drugs to a greater extent than other specialties, the lack of drugs to quickly suppress or stimulate the autonomic nervous system, provide pain relief or antibiotic coverage poses a serious challenge.

"All of a sudden, you have a life-critical procedure and you're using your second-best drug or a drug you're less familiar with," said Arjun Venkatesh, an assistant professor of emergency medicine at the Yale School of Medicine who co-authored the study.

Venkatesh said the Health Affairs analysis came about due to his own experience with recurring shortages of basic but vitally important medicines like saline intravenous solution.

The study found emergency medicine drug shortages decreased from 2002 to 2007 but rose significantly between January 2008 and March 2014. During that period, emergency drug shortages increased by 435 percent, from 23 drug shortages to 123. The subset of drugs used for life-saving interventions or high-acuity conditions increased 393 percent, and shortages of medications with no substitute grew by 125 percent.

Shortages of emergency-care drugs lasted an average of 242 days, the study found, and drugs to treat infectious diseases were the most commonly in short supply.

No reason was found for nearly half the drug shortages. When researchers contacted drug manufacturers, specific reasons were not provided.

In 2012, Congress approved the FDA Safety and Innovation Act, which attempted to curtail drugs shortages. The legislation required manufacturers to report drug shortages to the FDA and allowed the FDA to expedite inspections and reviews of alternative products and manufacturing facilities.

Even so, drug shortages have continued. Altering the economics of drugs could help, said Dr. Jesse Pines, a professor of emergency medicine and director of the Office for Clinical Practice Innovation at the George Washington University School of Medicine and Health Sciences.

Pines is an author of a 2015 study on which the Health Affairs analysis was based. Profit margins for acute care drugs are quite thin, and if one manufacturer stops producing a drug, another manufacturer likely won't pick up the slack quickly, he told the Washington Post.

In the new analysis, authors suggested tax credits, rebates and temporary market exclusivity as ways to boost supplies of generic injectable drugs.