A new study summarized in Reuters Health says that U.S. emergency rooms are increasingly running short on medications, including many that are needed for life-threatening conditions. Since 2008, the number of shortages has risen by more than 400 percent, researchers found. Half of all emergency room shortages were for life-saving drugs, and for one in 10 there were no available substitutes, they report in Academic Emergency Medicine. And a bad result in an emergency room can easily result in a higher workers’ compensation claim cost in the long run.

Half of the individual shortage incidents had no explanation, the authors found. The rest had a variety of systemic causes that add up to a U.S. drug supply too low to meet public demand.

“Drug shortages are of particular concern in emergency care settings where providers must rapidly treat ill and injured patients,” said lead author Kristy Hawley of the George Washington University School of Medicine and Health Sciences in Washington, D.C. “For most medications, substitutes exist but may not be as effective and may have more side effects, or providers may not have as much experience with them,” she told Reuters Health by email.

The researchers looked at U.S. data on drug shortages between 2001 and 2014. The information came from hospital doctors’ reports, and it’s possible there were additional unreported shortages, the authors note. The number of shortages declined steadily between 2001 and 2007 but began a sharp, continual rise in 2008. Of the 1,798 shortages reported over the 13-year period, 610, or about one third, were for drugs used in emergency medicine. Over half of these were shortages of drugs used as lifesaving interventions or for high-risk conditions. The average shortage duration for emergency drugs was nine months.

Drugs for treating infections were the most common ones to run low, with 148 shortages. Painkillers and drugs for treating overdoses and poisonings were also among the most common shortages. Hawley noted that a particularly problematic shortage was for nalaxone, the only injectable treatment for opiate overdose.

In nearly half of shortage incidents, the manufacturer did not give a reason for the shortage when contacted. For shortages with a known reason, about a quarter were due to manufacturing problems or delays, around 15 percent were caused by market supply and demand issues and about 4 percent were from problems with raw materials.

In 2013, the U.S. Food and Drug Administration released a plan to combat drug shortages. Last spring, the agency also released a mobile app for doctors and pharmacists to search for information about drug shortages.