In newly unsealed testimony, comedian Bill Cosby admitted to obtaining seven Quaalude prescriptions in the 1970s and keeping the drugs through the 1990s with the intent of using them on women he wanted to have sex with. Quaaludes, the brand name of prescription drug methaqualone, were transferred to Schedule I of the Controlled Substances Act (CSA) and banned in 1984. They were originally prescribed for insomnia, and also used as a sedative and muscle relaxant.

The United States Drug Enforcement Administration (DEA) defines Schedule I drugs as those with no currently accepted medical use and a high potential for abuse. “Schedule I drugs are the most dangerous drugs of all the drug schedules with potentially severe psychological or physical dependence,” the DEA’s website states. Other Schedule I drugs include heroin, ecstasy and LSD.

The first time a patient takes Quaaludes, the drug has a sedative effect that causes central nervous system depression similar to Ambien, said Jennifer K. Seltzer, PharmD, a clinical assistant professor at The University of Texas at Austin College of Pharmacy.

“It can cause a euphoria-type feeling— what’s described as a ‘relaxed, intimate mood,’ which may be the reason why it is abused by people, because of that particular quality,” Seltzer told FoxNews.com. She added that the drug causes relaxation, drowsiness, tiredness, and potentially dizziness.

The more a patient takes, the more central nervous system, respiratory and cardiac depression he or she will experience. In large overdoses it may even cause coma, said Jean Moon, PharmD, an assistant professor at the University of Minnesota College of Pharmacy.

As for the potency of Quaaludes used up to 20 years after prescription, Seltzer and Moon noted that without chemical analysis it’s hard to determine, but the pills likely still had an effect.

“Let’s say it takes three years for a drug to lose 10 percent of its potency… Maybe even after 15 years, it may still have 40 to 50 percent of its potency. If you give someone a couple of them, it could certainly still have some kind of impact on that person, but that is speculation on my part,” said Selzter, who added it made sense that Cosby’s Quaaludes may still have had an effect based on the way prescription drugs degrade.

"I wouldn't know for sure about the specific medicine [Cosby] saved from the 1970s, but most of the potency could still be there," Moon said. "I think most experts agree that many medications retain quite a bit of potency over time. Now, 20 years, I don't know."

When ingested, methaqualone attaches to the fat in the body. Traces have been found in urine after 21 days and in blood after seven days at regular doses.