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
All of the following agents are used in obesity except- 
Select and explain. 
A. Orlistat, B. Sibutramine, C. Olestra, D. Neuropeptide Y analogues
D: Neuropeptide Y analogues
Answer: D: Neuropeptide Y analogues 
Explanation: Ans. is `d' i.e., Neuropeptide Y analogues PHARMACOLOGICAL TREATMENT OF OBESITY o Antiobesity drugs act in either of two ways:? a) Reduce food intake (anorectic) b) Reduce absorption a) Reduce food intake 1. | Norepinephrine and serotonin in CNS (Central anorexients) o Augmentation of neurotransmission of norepinephrine and serotonin (5-HT, receptors) reduce caloric intake without a sense of deprivation. o Amphetamines, fenfluramine, dexfenfluramine, diethylpropion, mazindal, phenteramine and phendimetrazine increase release of norepinephrine in CNS. o Sibutramine blocks reuptake of both norephrine and serotonine resulting activation of 5-HT, receptrs. o Sibutramine is the only anorexiant that is currently approved by FDA for long term use. 2. NPY and AgRP antagonsits 3. MSH and CA agonists 4. Cannabinoid receptrs antagonist (Rimonabant) 5. Leptin analogues b) Reduce absorption Orlistat