This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Both fenfluramine and phentermine 
Select and explain. 
A. Produce central nervous system stimulation, B. Act to suppress appetite, C. Are effective in treating narcolepsy, D. Have been used in children with attention deficit disorders
B: Act to suppress appetite
Answer: B: Act to suppress appetite 
Explanation: . Both fenfluramine and phentermine have been successfully used, alone and in combination, for the treatment of obesity. They apparently reduce appetite by affecting the satiety centers in the hypothalamus. Whereas phentermine is a central nervous system (CNS) stimulant related to the amphetamines and is believed to act by releasing norepinephrine from CNS neurons, fenfluramine causes lethargy and sedation and acts by augmenting serotonin neurotransmission. For this reason, the drugs may be used together without causing excessive CNS stimulation or depression.