Welcome all to IS PHARMACOLOGY DIFFICULT Podcast! I am Dr Radhika Vijay, in today's episode, I will be conversing about Action Effect Sequence of Drugs in Pharmacodynamics. First of all, for your utter kind information, I want to tell you that Drug action and Drug effect are not synonymous. Drug action is the binding of drug to receptor and bringing about a conformational change, while on the other hand, Drug effect is the final biological response produced due to drug action occurring through a series of events in a stepwise organised manner. Hence to know more for one's knowledge, one should know that Receptor serves two important functions, firstly binding of the drug or ligand molecule after its specific identification, and secondly bringing about a final response after a conformational change. So all in all, we get to know that receptor has one ligand binding domain and another important one is effector domain. Then next I will tell you that there are 5 major categories or pathways of transducer mechanisms through which a receptor drug combo acts and produces response. Before this I will depict in my words a beautiful and simple diagram of a receptor which has external binding sites for agonist, competitive and non competitive antagonist, on inner side there is attached a transducer mechanism and finally connected to effector system leading to the response production. With all these important elaborate information, I will wind up today's episode, till next one do follow me here, stay tuned, do rate and review on ITunes, Apple podcasts, thank you!!