Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode, with a great quote from a great traveller, we will break today's ice with a brand new topic quite different from what we have doing in the past, and lo!  Its known as First pass metabolism also called as Presystemic metabolism. Firstly after defining first pass metabolism, I will be listing the routes of drug administration that surpass the first pass metabolism, then I will be explaining the concept of Extraction ratio of liver, in detail with the help of an equation and then in turn I will be deriving an equation of Bioavailability fro the former concept, Then I will be throwing some light on important attributes of this presystemic metabolism in around all in all 4 to 5 bullet points, and the concluding part of episode will be made up with a beautiful table under three major heads listing drugs having low, intermediate and high first pass metabolism and their most important examples.Hope you all like it, till next episode, do follow me here, do rate and review on ITunes, Apple podcasts, stay tuned thank you!!