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': 'A patient diagnosed with deep vein thrombosis is being treated with heparin. Which of the following test will you order to adjust its dosage? \nSelect and explain. \nA. Platelet count, B. Prothrombin time, C. Bleeding time, D. Activated partial thromboplastin time', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Heparin\xa0must\xa0be\xa0administered\xa0subcutaneously or intravenously, because the drug does not readily cross\xa0membranes. The LMWHs\xa0are\xa0administered\xa0subcutaneously.\nHeparin is often initiated as an intravenous bolus to achieve immediate anticoagulation. This is followed by lower doses or\xa0continuous\xa0infusion\xa0of\xa0heparin,\xa0titrating\xa0the\xa0dose\xa0so\xa0that\xa0the activated partial thromboplastin time (aPTT) is 1.5- to 2.5-fold that of the normal control. \xa0\nThe half-life of heparin is approximately 1.5 hours, whereas the half-life of the LMWHs is longer than that of heparin, ranging from 3 to 12 hours.\nKey Concept:\xa0\nThe aPTT is the standard test used to\xa0monitor\xa0the extent\xa0of\xa0anticoagulation\xa0with\xa0heparin.', 'role': 'assistant'}]