Isolated from opium by the German chemist F. W. A. Sertürner around 1804, morphine (named after Morpheus, the Greek god of sleep and dreams) was used to treat opium addicts. Invented by Bayer Pharmaceuticals in 1898, heroin (derived from the Greek word for hero) was used to treat morphine addicts.

Overworked and suffering from chest and stomach conditions, Emperor Marcus Aurelius took a prescription from his physician, Galen, for opium. According to Galen, the emperor did not like that the drug made him drowsy, so he stopped taking it. Then he found himself unable to sleep, so he started taking it again.