A patient presented with dry mouth, dry hot skin and dilated pupils, cause could be:
Correct Answer: Anticholinergic poisoning
Description: 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.
Category:
Pharmacology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now