Clinical signs of atropine Intoxication are all EXCEPT:
**Core Concept**
Atropine is a muscarinic receptor antagonist that inhibits the parasympathetic nervous system's (PNS) effects, leading to anticholinergic toxicity. It primarily affects the central and peripheral nervous systems, causing a range of symptoms.
**Why the Correct Answer is Right**
Atropine intoxication leads to a spectrum of symptoms due to its anticholinergic properties. It causes tachycardia, mydriasis (pupil dilation), dry mouth, and urinary retention due to the blockade of muscarinic receptors in the heart, eye, salivary glands, and bladder. Additionally, atropine can cause hallucinations, confusion, and delirium by affecting the central nervous system.
**Why Each Wrong Option is Incorrect**
**Option A:** Tachycardia is a characteristic sign of atropine intoxication due to the blockade of muscarinic receptors in the heart. This leads to unopposed sympathetic stimulation, resulting in an increased heart rate.
**Option B:** Mydriasis is a classic sign of atropine intoxication due to the blockade of muscarinic receptors in the eye, leading to pupil dilation.
**Option C:** Dry mouth is also a characteristic sign of atropine intoxication due to the blockade of muscarinic receptors in the salivary glands, leading to decreased saliva production.
**Option D:** Bradycardia is the opposite of what occurs in atropine intoxication. Instead, tachycardia is expected due to the blockade of muscarinic receptors in the heart, leading to unopposed sympathetic stimulation.
**Clinical Pearl / High-Yield Fact**
Remember the "hot as a hare, blind as a bat, dry as a bone, red as a beet" mnemonic to recall the classic signs of anticholinergic toxicity: tachycardia (hot), mydriasis (blind), dry mouth (dry), and flushing (red).
**Correct Answer: D. Bradycardia. Bradycardia**