According to the FDA, the undeclared sildenafil poses a serious health risk because it may interact with nitrates found in some prescription drugs, such as nitroglycerin. This may lower blood pressure to dangerous levels, particularly for people with diabetes, high blood pressure, high cholesterol or heart disease who often take nitrates.

The FDA issued its most serious risk classification—Class I—on March 11, according to the official enforcement notices.

This will be Prasad’s second exit from the FDA during the current Trump administration. In July, he resigned amid his controversial handling of a gene therapy treatment for Duchenne muscular dystrophy, as well as criticism from far-right activist Laura Loomer, who called Prasad a “leftist saboteur.” He was reinstated less than two weeks later.