This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Benzodiazepines differ from barbiturates in the following aspects except: 
Select and explain. 
A. They have a steeper dose response curve, B. They have higher therapeutic index, C. They have lower abuse liability, D. They do not induce microsomal drug metabolizing enzymes
A: They have a steeper dose response curve
Answer: A: They have a steeper dose response curve 
Explanation: BENZODIAZEPINES (BZDs) BZDs produce a lower degree of neuronal depression than barbiturates. They have a high therapeutic index They have lower abuse liability: tolerance is mild, psychological and physical dependence, drug seeking and withdrawal syndrome are less marked BZDs do not alter disposition of other drugs by microsomal enzyme induction A specific BZD antagonist flumazenil is available which can be used in case of poisoning. The slope of the DRC is also impoant. A steep slope indicates that a moderate increase in dose will markedly increase the response (dose needs individualization), while a flat one implies that little increase in response will occur over a wide dose range (standard doses can be given to most patients). Barbiturates have steep DRC and BZDs have a flat DRC(dose response curve). Ref:- kd tripathi;pg num:-55, 401