Drug of choice in Belladonna poisoning is –
**Core Concept**
Belladonna poisoning is caused by the ingestion of plants containing the tropane alkaloids atropine and scopolamine. The primary mechanism of toxicity is the inhibition of the parasympathetic nervous system, leading to anticholinergic effects such as tachycardia, mydriasis, and dry mouth.
**Why the Correct Answer is Right**
The drug of choice in Belladonna poisoning is physostigmine, a reversible cholinesterase inhibitor that can counteract the anticholinergic effects of atropine and scopolamine. Physostigmine increases the concentration of acetylcholine in the synaptic cleft, thereby restoring parasympathetic tone and alleviating symptoms. This is particularly effective in cases of severe poisoning where supportive care and benzodiazepines are insufficient.
**Why Each Wrong Option is Incorrect**
**Option A:** Atropine is the active ingredient in Belladonna and would exacerbate the symptoms of poisoning.
**Option B:** Benzodiazepines may be used to manage seizures, but they do not address the underlying anticholinergic toxicity.
**Option C:** Activated charcoal may be used to prevent further absorption of the toxin, but it does not treat established poisoning.
**Clinical Pearl / High-Yield Fact**
Physostigmine can cause bradycardia and seizures in high doses, making careful titration and monitoring essential in its administration.
**Correct Answer: D. Physostigmine**