History of clonidine

Around 1960: Clonidine, an α2-agonist, was developed as a nasal decongestant that worked by vasoconstriction.

Administered to a secretory she developed following features along with good nasal decongestant effect at low concentration 

• Fell asleep for 24 h
• Low blood pressure
• Marked bradycardia
• Dryness of the mouth

1966: introduced in clinical practice reformulated for hypertension.

Source: Helmut Stähle,

A historical perspective: development of clonidine, Best Practice & Research Clinical Anaesthesiology, Volume 14, Issue 2, 2000, Pages 237-246, ISSN 1521-6896,

https://doi.org/10.1053/bean.2000.0079.

(http://www.sciencedirect.com/science/article/pii/S152168960090079X)