This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Substance abuse, Subject name: Psychiatry
[{'content': 'All are anti-craving agents for alcohol except \nSelect and explain. \nA. Lorazepam, B. Naltrexone, C. Topiramate, D. Acamprosate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Anti-craving agentsAcamprosate, naltrexone and SSRIs (such as fluoxetine) are among the medications tried as anti-craving agents in alcohol dependence. Acamprosate (the Ca++ salt of N-acetyl-homo taurinate) interacts with NMDA receptor-mediated glutamatergic neurotransmission in the various brain regions and reduces Ca++ fluxes through voltage-operatedchannels. Naltrexone (oral opioid receptor antagonist) probably interferes with alcohol-induced reinforcement by blocking opioid receptors. Fluoxetine (and other SSRIs) have been occasionally used as anti-craving agents in their usual antidepressant doses. Ref: A Sho Textbook of Psychiatry, Niraj Ahuja, 7th Edition, pg. no.42 Lorazepam is a benzodiazepine class of drug used for the treatment of alcohol withdrawal.', 'role': 'assistant'}]