This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Maximum first pass metaboilsm is seen by which route ? \nSelect and explain. \nA. Intravenous, B. Interaaerial, C. Rectal, D. Oral', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Oral First pass metabolism is seen with oral and rectal routes. Maximum first pass metabolism is seen with oral route. In rectal route, drug absorbed into external hemorrhoidal veins bypasses liver, but not that absorbed into internal haemorrhoidal veins -First pass metabolism occurs, but less than oral route (avoids first pass metabolism to 50%). Most rapid onset of action is seen with I. route. Bioavailability by I. V route is 100%.", 'role': 'assistant'}]