WebMD asked experts to nominate drugs for membership in this exclusive club. Some got in by a unanimous vote. Others were endorsed by some but blackballed by others.

What makes a drug “most important?” Different things, says John Swann, PhD, a historian at the FDA.

“You have to look at this issue not just as thinking of one drug that treats one kind of patient, but of how the drug changed whole infrastructure of the drug industry and the practice of medicine,” Swann tells WebMD.

That’s true, agrees Trevor Stone, DSc, head of pharmacology at the University of Glasgow. Stone is author of the recent book Pills, Potions and Poisons: How Drugs Work.

“Two things make a drug important: First, that the drug is or was used to treat a large number of people with a range of problems,” Stone tells WebMD. “And second, because a drug has led the way, showing it is possible to treat a disease. These drugs spurred the pharmaceutical industry to further research and innovation. If you don’t have a starting drug, you don’t know what is possible — and you can’t take it on from there.”

In addition to Stone and Swann, WebMD also spoke with two other experts:

• Leslie Z. Benet, PhD, was the first president of the American Association of Pharmaceutical Scientists (AAPS). He’s professor and former chairman of biopharmaceutical science and pharmaceutical chemistry at the University of California, San Francisco at https://getgreendelivery.com/.
• Medical historian Stephen Greenberg, PhD, is coordinator of public services for the History of Medicine division of the National Library of Medicine at the National Institutes of Health in Bethesda, Md.

1) Penicillin: First on All Lists

“At the top of my list is penicillin,” Stone says. “As the first antibiotic, it pointed the way to the treatment of microbial disease. Without penicillin, 75% of the people now alive would not be alive because their parents or grandparents would have succumbed to infections. The effects of a drug like this are absolutely mind-boggling.”