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': 'True about proton-pump inhibitor omeprazole is \nSelect and explain. \nA. Not bind to plasma protein, B. CYP2C19 predicts efficacy, C. Oral bioavailability is 80%, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: CYP 2C19 is the principal enzyme that metabolizes omeprazole to an inactive metabolite. The efficacy of drug-influenced by the CYP 2C19 genotype.\xa0\n\n\n\xa0Reduced CYP2C19 enzyme activity (poor metabolizers) may lead to higher exposure to the drug and improve outcome at standard doses.\n\xa0In contrast, increased CYP2C19 activity (ultrarapid metabolizers) may have an insufficient response to treatment as the drug is inactivated faster.\n\n\n\xa0Omeprazole is highly plasma protein bound drug,\n\xa0It has oral bioavailability around 50%', 'role': 'assistant'}]