Employees of the White House medical unit said that it often operated like a "grab and go" clinic, allowing mid-level staffers to senior officials to acquire prescription drugs without being seen by a doctor, according to a report by CNN.

Five current and former medical unit staffers, who wished to remain anonymous, told CNN that prescription medications were given to White House staffers, sometimes without medical consultations by a doctor. This practice was allegedly endorsed by Rear Adm. Ronny Jackson, who withdrew his nomination to lead the Department of Veterans Affairs on Thursday following accusations that he wrecked a government vehicle while drunk and handed out opioids to a White House staffer, garnering him the nickname "candy man."

Jackson denied the allegations. Press secretary Sarah Huckabee Sanders said that Jackson remains a doctor in the U.S. Navy assigned to the White House. President Donald Trump defended Jackson Thursday morning in an interview on "Fox & Friends," saying there was "no proof" behind the accusations.

However, Sen. Jon Tester (D-Mont) wants the Senate to continue investigating Jackson, according to an article in USA Today. On Wednesday, the Senate Veterans Affairs Committee minority staff released a two-page memo that listed the allegations made against Jackson.

One medical unit employee said that there was a "loose control of the controlled medications" under both the Obama and Trump administrations. They said that staffers were often freely granted antibiotics and other prescription medications.

"We would just hand them out," one source told CNN. "They'd come in and say, 'Hey, can I have an Ambien?' And we would just hand them out. Without having to sign a thing. We all had a huge problem with it."

Another person within the medical unit said it was "standard practice" for parents to pick up Ambien, a sleeping medicine, and Provigil, a wakefulness agent, even for their children.

The White House did not immediately respond to CNBC's request for comment.

Read CNN's full report here.