Understanding sympathetic nervous had never been easy. (It doesn’t in any way mean, we have mastered para-sympathetic !). As physicians and cardiologists, we are expected to know the updated adrenergic, dopaminergic, imidazoline receptors etc. We need to know at-least an overview of its current nomenclature, area of distribution, benefits of blocking and stimulating them. Unfortunately, many of us consider it as student stuff and too theoretical for a busy cardiologist.
A realistic scenerio
Then one fine day, an I-pad wielding ,medical representative would come, late in night and teach us about a new drug called Moxonidine. “Sir this is a combined alpha and Imidazoline-1 agonist. Just .2 mg is enough sir to treat any refractory HT” We nod our heads sheepishly, wondering what is that Imidazoline ? Why is this guy is saying alpha agonist* ?
*So far I had been thinking only alpha blockers, have anti-hypertensive action. It took few moments to make some sense . Oh, okay, I got it, Clonidine and Prazosin are entirely different groups of drugs, though they act on alpha receptors—one stimulating and other blocking at different sites.
This post is meant to avoid such embarrassing situations.

Final message
Let us learn new things every day , but never think, reviewing what we read in the past is a mean academic activity.
Reference
1.Paul A. Insel, M.D Adrenergic Receptors- Evolving Concepts and Clinical Implications N Engl J Med 1996;334:580-585
2.Campbell lain C, McWilliam JR, Adamson P. Central adrenergic receptors. Journal of Psychopharmacology. 1987;1(2):55-66. doi:10.1177/026988118700100201

