Pharmacology Cholinergic drug which acts on hea by decrease in levels of cAMP and due to opening of K+ channels is? A Methacholine B Oxotremorine C Bethanechol D DMPP 💡 Explanation Cholinergic drug which acts on hea by decrease in levels of cAMP and due to opening of K+ channels is? ✓ Correct Answer: A. Methacholine