Fen-phen was an obesity medication that caused valvular heart disease and pulmonary hypertension. If you've never heard of fen-phen, check out this article from Sept. 23, 1997 in the New York Times: https://archive.is/ottWQ

Wyeth set aside $21.1 billion to cover the lawsuits. https://archive.is/k3Go4

It was kind of a big deal. Not many people younger than ~30 have heard of it for some reason.