A shortage of chemotherapy drugs is causing thousands of patients to experience delays in treatment for cancer and other diseases.

Hundreds of drugs are in short supply in the United States, and chemotherapy drugs are among the top five meds impacted by the shortage, according to an American Cancer Society (ACS) news release.

“The shortage of certain cancer drugs has become a serious and life-threatening issue for cancer patients across the country,” said ACS CEO Karen Knudsen, MBA, PhD, in a statement. “A number of the drugs included in the shortage don’t have an effective alternative. As first-line treatments for a number of cancers, including triple-negative breast cancer, ovarian cancer and leukemia often experienced by pediatric cancer patients, the shortage could lead to delays in treatment that could result in worse outcomes.”

While some drugs are in short supply due to supply chain interruptions—for example, the United States relies on India and China for many medicines and drug ingredients—as well as quality control issues that have shut down some manufacturing, the reasons for the shortage of generics are less clear.

According to The New York Times (NYT), the shortage of generic forms of chemotherapy to treat lung, breast, ovarian and bladder cancers has led to increasing concerns from public health officials. ACS warned earlier this month that delays in care due to the shortage could result in worse outcomes for patients.

“If these drugs are not available, people are going to get inferior care,” said William Dahut, MD, ACS’s chief medical officer. “That’s the bottom line. These aren’t third- or fourth-line drugs where there are multiple other agents around. These are used up front for people you are trying to cure.”

Hospitals are also experiencing shortages of drugs that reverse lead poisoning, the sterile fluid needed to stop the heart for bypass surgery, certain antibiotics and even children’s Tylenol due to the combined impact of last fall and winter’s  flu, respiratory syncytial virus (RSV) and COVID-19 cases.

The Society of Gynecologic Oncology outlined strategies for allocating limited supplies of drugs for gynecologic cancers and warned that disparities in care could worsen without proper planning. According to the NYT, a Society of Gynecologic Oncology survey found that doctors in 35 states responded that they had “little to no supply of key chemotherapy drugs, even at large cancer centers and teaching hospitals.”

The shortage has warranted a response from the White House and Congress, which, together, are seeking to identify why the generic drug market—which accounts for approximately 90% of domestic prescriptions— is in such dire straits according to the NYT.

James McKinney, a spokesman for the Food and Drug Administration (FDA), told the NYT that the White House must work with national security and economic and health officials on the larger issue of longstanding drug supply breakdowns. Some officials suggest implementing tax incentives for generic drugmakers and increased transparency regarding generic drug quality.

“We urge the industry to work with medical practitioners to help identify alternatives where possible to ensure that cancer patients’ treatments are not delayed,” Knudsen said.