ARIZONA,
Blessedly there were a couple. Of course the most noteworthy was aspirin. Arthritics who were taking 15 or so a day for pain and inflammation had the darndest side effect. They almost NEVER died of heart attacks.
There was also one (whose name escapes me) that had the darndest side effect: frequent long lasting erections! (Such torment

)
But you're right....they're rare indeed.