A 45-year-old man with chronic alcoholism appears in the emergency department with disorientation and confusion. A neurologic examination shows ataxia and disconjugate eye movements. What is the most appropriate treatment?

Choice A reason: Promethazine is an antiemetic and sedative, but it does not address the underlying neurologic symptoms associated with chronic alcoholism. It is not appropriate for treating Wernicke’s encephalopathy or thiamine deficiency. Choice B reason: Thiamine deficiency is common in chronic alcoholism and can lead to Wernicke’s encephalopathy, characterized by confusion, ataxia, and ophthalmoplegia. Thiamine supplementation is the first-line treatment and should be administered promptly to prevent progression to Korsakoff syndrome. Choice C reason: Lorazepam may be used for alcohol withdrawal symptoms but does not treat the neurologic deficits caused by thiamine deficiency. It may worsen confusion and sedation if not properly indicated. Choice D reason: Potassium supplementation may be necessary in alcoholics due to electrolyte imbalances, but it does not address the acute neurologic symptoms. It is not the most appropriate immediate treatment in this scenario.