Epinephrine analogues.

Tyramine was the first epinephrine analogue to be introduced into medicine, in the early 1900s. It was followed by ephedrine and pseudoephedrine in the 1920s and by the amfetamines a decade later. The popularity of the amfetamines grew throughout the 1930s and 1940s; after that, there was a slowly dawning realization that they were being widely abused. Isoprenaline, introduced in the 1950s, was soon recognized as superior to epinephrine when used as an inhaler by asthmatics, and it remained the drug of choice for the relief of bronchospasm until around 1970. Orciprenaline, which featured an orcinol system, had a long duration of action and was active by mouth; Boehringer marketed it both as an inhaler and as a syrup for the prophylaxis of bronchospasm. The greatly superior bronchodilators salbutamol and terbutaline, launched in 1968 and 1970, respectively, incorporate further variation on the molecular theme that had led to the development of orciprenaline.