What was the first effective local anesthetic?

Cocaine is recognized as the first effective local anesthetic due to its ability to block nerve conduction, providing localized pain relief when applied to mucous membranes and tissues. Its use in medicine became prominent in the late 19th century, particularly after Carl Koller, an ophthalmologist, demonstrated its effectiveness in eye surgery in 1884. This breakthrough ushered in a new era in medical procedures, allowing for surgeries to be performed with reduced pain for patients without affecting their overall consciousness.

While morphine is a potent analgesic used for pain relief, it does not function as a local anesthetic, as it does not block nerve conduction in a localized manner. Quinine has historical significance as a treatment for malaria and does not provide local anesthesia. Heroin, although related to morphine and used for its euphoric effects, is not used as a local anesthetic and is primarily known for its addictive properties. Cocaine's unique properties established it as the first local anesthetic, paving the way for the development of other synthetic local anesthetics later on.