When German pharmacist Friedrich Wilhelm Seturner isolated morphine from opium in 1805, a new era in drug production and use began. Soon many other new drugs were obtained by isolating active elements from crude drugs. One of these was codeine, which was discovered and named by Pierre-Jean Robiquet (1780-1840) in 1832. Like morphine, codeine is an alkaloid (a naturally occurring constituent) of opium. The chemical works of E. Merck, established in 1827 to manufacture morphine, began producing codeine the same year the drug was discovered. Years later, Thomas Anderson (1819-1874), a professor of chemistry at the University of Glasgow, clarified the elemental makeup of codeine.

Today, codeine is commonly used in prescription drugs in combination with aspirin or acetaminophen to relieve pain, which it does by altering the way the brain reacts to painful sensations. It is also a common ingredient in prescription cough medicines, where it acts as a cough suppressant. Codeine can be addictive, although less so than morphine, which is why codeine is only available by prescription.