When the COVID-19 pandemic first hit, there were limited supplies of select items, like toilet paper and hand sanitizer. But now, some common prescription medications are facing shortages in the United States, and experts are pointing the finger at the pandemic.

The U.S. is currently seeing shortages in true wallet slot a range of common prescription medications, including epinephrine auto-injectors (used to counteract severe allergic reactions), oral inhaler albuterol, antibiotics azithromycin and doxycycline, and the diuretic chlorothiazide, according to the Food and Drug Administration (FDA). Anti-anxiety and anti-depressant medication sertraline hydrochloride (Zoloft) has also been in shortage for months.What’s going on here? In the case of Zoloft, the FDA simply says that the drug shortage issue is “due to the impacts caused by COVID-19.” The American Society of Health-System Pharmacists website also reports that there are some shortages of albuterol and azithromycin due to increased demand. That’s likely “due to COVID,” Emily R. Aboujaoude, clinical assistant professor of pharmacy practice and administration at the Rutgers Ernest Mario School of Pharmacy, tells Life.

But experts say issues with the other medications are likely tied to the pandemic as well. Robert Weber, administrator for pharmacy services at The Ohio State University Wexner Medical Center and assistant dean for Medical Center Affairs at The Ohio State University College of Pharmacy, tells that the following are usually to blame for drug shortages happening now:

A shortage of the active pharmaceutical ingredient

Delays in getting the active pharmaceutical ingredient, either from other countries or from within the U.S.

Possible closures or delays due to COVID-19 spread in a plant or manufacturing facility

“Shortages can also be because there is increased use,” Jamie Alan, an assistant professor of pharmacology and toxicology at Michigan State University, tells Yahoo Life, citing current shortages of antacids like Pepcid and famotidine to combat stomach issues as examples.