Cancer patients are currently facing a nationwide shortage of cancer-fighting chemotherapy drugs.

Amanda Nickles Fader, a gynecologic oncologist at Johns Hopkins Medicine, recently told Scientific American that hospitals nationwide will need to generate solutions to “likely the worst chemotherapy drug shortage crisis that the U.S. has ever seen.”

Doctors are currently rationing their shrinking supplies of oncology drugs. Some are skimping on doses or replacing scarce drugs with inferior alternatives, reports STAT News.

Fader claims she has heard of patients desperate to transfer to a different treatment center, even out of state, to access chemotherapy drugs. Their effort failed since the drug shortage has impacted hospitals nationwide, per Scientific American.

Drug shortages, in general, are a huge problem in health care. Researchers estimate drug shortages typically impact half a million patients and often lead to higher drug prices, according to the Federal Office of the Assistant Secretary for Planning and Evaluation.

The treatments most heavily impacted by the current cancer drug shortage include “the platinum-based injectable drugs carboplatin and cisplatin, which are used to treat breast cancer, gynecologic cancers, testicular cancer, head and neck cancers and bladder cancer,” reports the Scientific American.

In a recent statement, the White House noted that a lack of generic options and manufacturing-related challenges are key factors fueling the drug shortages.

“Unfortunately, the United States is currently experiencing a shortage of 15 cancer drugs due to manufacturing and supply chain issues. Three of these drugs — cisplatin, carboplatin, and methotrexate — are widely used generic drugs and have been staples of cancer treatment for decades,” the White House wrote.

“Several generic oncology drug manufacturers have discontinued products over time for economic reasons. And, in the last year, manufacturing site closures cut the U.S. supply of these three drugs nearly in half. These supply issues have had serious impacts on patients in the form of delayed and altered treatments,” the statement continued.

A May survey from the National Comprehensive Cancer Network found that among 27 cancer treatment centers, 93% reported a carboplatin shortage and 70% reported a cisplatin shortage.

A productive solution has yet to be put into play, but several nonprofit organizations have stepped up to fill in the gap during the meantime. Angels for Change, for example, is an organization that help patients source the drugs they require for treatment.

Several drugs, including anti-inflammatory drugs and hormonal medications, are also currently in short supply, according to a recent survey of more than 1,100 pharmicists conducted by the American Society of Health System Pharmacists.