What are magic bullets in pharmaceutical terms?

The German scientist Paul Ehrlich, considered the father of chemotherapy, originally coined the term magic bullet in the 19th century to refer to arsenic containing chemicals that showed the remarkable ability to cure syphilis — a sexually transmitted disease. He proposed the seminal idea that each disease must be treated with a chemical specific for that disease. His greatest contribution was the discovery of Salvarsan — the first effective treatment for syphilis. In the pharmaceutical industry, the term magic bullets is used to refer to antibiotics that are used to treat infectious diseases like pneumonia, typhoid, tuberculosis, malaria etc. The remarkable specificity with which antibiotics kill diseasecausing micro-organisms without causing major side effects in humans and animals, combined with the ability to cure major infectious diseases that were previously considered incurable, earned them the name magic bullets.