A patient presented with dry mouth, dry hot skin and dilated pupils, cause could be:

Ans. A. Anticholinergic poisoningRef: Harrison's Principles of Internal Medicine 19th/ed, Table 473-e2 and e4Explanation# Dry mouth, dry hot skin and dilated pupils (mydriasis), all are features of anticholinergic poisoning.# Understanding of sympathetic and parasympathetic actions is of prime importance in understanding cholinergic or anti cholinergic poisoning.# In cholinergic poisoning - symptoms resembling parasympathetic activity appear.# In anticholinergic poisoning - parasympathetic activity is inhibited and as you know each organ has both sympathetic and parasympathetic innervations; inhibition of parasympathetic actions leads over expression of uninhibited sympathetic activity, in other words symptoms of sympathetic over-activity are seen.# Features of cholinergic and anticholinergic poisoning is as follows: Anticholinergic poisoningCholinergic poisoningMechanismInhibition of central and postganglionic parasympathetic muscarinic cholinergic receptorsInhibition of AChE leading to increased synaptic ACh at muscarinic and nicotinic cholinergic receptor sitesExamplesAtropine, hyoscyamine, scopolamine* Carbamates (aldicarb, carbaryl, etc.)* Drugs (neostigmine, tacrine, etc.)* Nerve gases (sarin, soman, tabun)* Organophosphates (diazinon, chlorpyrifos, malathion)Features1.Physiologic stimulation: Grade1 Anxious, irritable, tremulous; vital signs normal; diaphoresis, flushing or pallor, mydriasis, and hyperreflexia sometimes present. Grade 2 Agitated; may have confusion or hallucinations but can converse and follow commands; vital signs mildly to moderately increased.Grade 3 Delirious; unintelligible speech, uncontrollable motor hyperactivity; moderately to markedly increased vital signs; tachyarrhythmias possible.Grade 4 Coma, seizures, cardiovascular collapse.1.Physiologic depression:Grade 1 Awake, lethargic, or sleeping but arousable by voice or tactile stimulation; able to converse and follow commands; may be confused.Grade 2 Responds to pain but not voice; can vocalize but not converse; spontaneous motor activity present; brainstem reflexes intact.Grade 3 Unresponsive to pain; spontaneous motor activity absent; brainstem reflexes depressed; motor tone, respirations, and temperature decreased. Grade 4 Unresponsive to pain; flaccid paralysis; brainstem reflexes and respirations absent; cardiovascular vital signs decreased. 2.Dry skin and mucous membranes,decreased bowel sounds, flushing, and urinary retention; myoclonus and picking activity.3.Central effects may occur without significant autonomic dysfunction.2.Muscarinic signs and symptoms:Seizures, excessive secretions (lacri- mation, salivation, bronchorrhea and wheezing, diaphoresis), and increased bowel and bladder activity with nausea, vomiting, diarrhea, abdominal cramps, and incontinence of feces and urine.3.Nicotinic signs and symptoms: Hypertension, tachycardia, muscle cramps, fasciculations, weakness, and paralysis. Death is usually due to respiratory failure.TreatmentPhysostigmine, (AChE inhibitor), for delirium, hallucinations, and neuromuscular hyperactivity. C/l are asthma and non-anticholinergic cardiovascular toxicity (e.g., cardiac conduction abnormalities, hypotension, and ventricular arrhythmias).Atropine for muscarinic signs and symptoms;2-PAM, a cholinesterase reactivator, for nicotinic signs and symptoms due to organophosphates, nerve gases, or an unknown anticholinesterase.