Antibiotic
A type of drug that was (officially) discovered in 1928 when Sir Alexander Fleming was cleaning out his petri dishes then saw a mold on one of them. He studied it, and noticed that all of the bacteria around the mold had been killed. Now, we use these "wonder drugs" to save people who (over a hundred years ago) would have died a painful death from bacterial infections. Now, unfortunately, they are overused and used when unnecessary, and can lead to antibiotic resistance. Includes penicillin, amoxicillin, streptomycin, neomycin, paromycin, cefepime, cefprozil, aztreonam, cifprofloxacin, etc.
Example:
Doctor: You have strep throat, so I will be prescribing you a ten-day antibiotic.
Patient: Thank you, Docto. Now my throat won't be sore anymore.
Doctor: You have strep throat, so I will be prescribing you a ten-day antibiotic.
Patient: Thank you, Docto. Now my throat won't be sore anymore.