A 40-year old man presents to casualty with history of regular and heavy use of alcohol for ten years and morning drinking for one year. The last alcohol intake was three days back. There is no history of head injury or seizures. On examination, there is no icterus, sign of hepatic encephalopathy or focal neurological sign. The patient had coarse tremors, visual hallucinations and had disorientation to time. Which of the following is the best medicine to be prescribed for such a patient?

**Core Concept**
The patient is presenting with symptoms of alcohol withdrawal, specifically delirium tremens (DTs), which is a severe and potentially life-threatening condition that requires prompt medical attention. Delirium tremens typically occurs 48-72 hours after the last drink in individuals with a history of chronic and heavy alcohol use.

**Why the Correct Answer is Right**
The patient's symptoms, including coarse tremors, visual hallucinations, and disorientation to time, are characteristic of delirium tremens. Benzodiazepines, such as chlordiazepoxide, are the first-line treatment for alcohol withdrawal and delirium tremens due to their efficacy in reducing symptoms and preventing seizures. Chlordiazepoxide works by enhancing the effect of gamma-aminobutyric acid (GABA) at the GABA_A receptor, which helps to stabilize the neuronal membrane and reduce excitatory neurotransmission.

**Why Each Wrong Option is Incorrect**
**Option A:** Phenobarbitone is a barbiturate that can be used to manage seizures but is not the first-line treatment for delirium tremens due to its potential for dependence and respiratory depression.
**Option B:** Haloperidol is an antipsychotic that can be used to manage agitation and hallucinations but can exacerbate delirium tremens and should be used with caution in this context.
**Option C:** Metronidazole is an antibiotic that is not indicated for the treatment of delirium tremens.

**Clinical Pearl / High-Yield Fact**
Benzodiazepines, such as chlordiazepoxide, should be initiated in a hospital setting for patients with delirium tremens, as they can precipitate respiratory depression and other adverse effects if used inappropriately.

**Correct Answer:** C. Chlordiazepoxide.

✓ Correct Answer: A. Diazepam