Isolated early in the 1800's. Morphine was named after the Greek god Morpheus.This drug alleviates severe pain after major trauma has been done to the body.
The discovery of Insulin in the 1916 was a major breakthrough in medicine. Romanian physiologist Nicolas C. Paulescu. He isolated a substance called Pancrein.
Austrian Scientist Ludwig Haberlandt published a paper about using contraceptives for animals. Tested a hormone for clinical trials but his work came to a sudden end because of his suicide. First birth control pill was approved in 1960.
Nitrogen Mustards: Developed in the 1920's for chemical warfare. The compound HN-2 or better known as Mechlorethamine became the first drug approved by the FDA to treat Cancer.
FDA approved the Drug Zidovudine aka AZT. This drug was a major breakthrough for the fight against HIV/AIDS. It did not cure the disease but prolonged the lives of those affected. Because of this drug HIV related deaths declined in the early 21st centruy
I think out of all seven drugs Penicillin was the most important drug created. Penicillin has saved so many lives and curated a whole industry dedicated to fighting bacterial infections.