Sympathomimetic Amines

Abstract

Sympathomimetic therapy started serendipitously in 1900 when desiccated adrenal gland was given to patients with asthma “to reduce oedema of the bronchial mucosa” and was found to be effective. Within 2 years the active substance had been isolated and purified, and variously named adrenaline, suprarenin and epinephrine. Synthetic compounds were subsequently produced, ephedrine in the 1920s and isoprenaline in 1940. The various sympathomimetic amines available in the 1940s were known to have different and sometimes opposite effects on different tissues. The reason for these anomalies became apparent in 1948 when Ahlquist identified two receptors subserving different functions, which he named α-and β-adrenoceptors. Subsequently, Lands et al. in 1967 were able to subdivide β-receptors into β₁- and β₂-adrenoceptors and to show that β₂-receptor stimulation was responsible for bronchodilatation. This paved the way for the introduction of more β₂-selective sympathomimetic amines in the 1960s.