Ipratropium is a nonselective antimuscarinic drug. It causes bronchodilation by obstructing the activity of acetylcholine-initiated activation of guanyl cyclase, henceforth decreasing development of cyclic guanosine monophosphate (cGMP) at parasympathetic site.
Salbutamol initiates adenyl cyclase, the chemical that activates the creation of cyclic adenosine-3′, 5′- monophosphate (cAMP). Increased cAMP prompts initiation of protein kinase A, which represses phosphorylation of myosin and brings down intracellular ionic Ca fixations, bringing about smooth muscle relaxation.
