Clinical Toxicology Lecture 2 PDF

Al-Mustaqbal University College Department of Pharmacy 5th stage/2024 Clinical Toxicology Lecture: 2 Anticholinergic Toxicity We a a m J. A b b a s Clinical Toxicology 5th stage Al-Mustaqbal University /College of Pharmacy Weaam J. Abbas  Outline...

Al-Mustaqbal University College Department of Pharmacy 5th stage/2024 Clinical Toxicology Lecture: 2 Anticholinergic Toxicity We a a m J. A b b a s Clinical Toxicology 5th stage Al-Mustaqbal University /College of Pharmacy Weaam J. Abbas  Outline Multiple Anticholinergic toxicity ? organ adverse effect Autonomic Nervous System Toxidrome Clinical Manifestation : Clinical Manifestation : Management and Antidote 2  Autonomic nervous system 3 Clinical Toxicology 5th stage Al-Mustaqbal University College of Pharmacy Weaam J. Abbas  Anticholinergic Drug Toxicity Cholinergic antagonist is an agents that bind to cholinorceptors (muscarinic or nicotinic) and prevent the effects of acetylcholine (ACh) and other cholinergic agonists. The most clinically useful of these agents are selective blockers of muscarinic receptors. The effects of parasympathetic innervation are, thus, interrupted, and the actions of sympathetic stimulation are left unopposed. 4 Clinical Toxicology 5th stage Weaam J. Abbas  Toxidrome and clinical manifestations Anticholinergic syndrome is produced by the inhibition of cholinergic neurotransmission at muscarinic receptor sites. It commonly follows the ingestion of a wide variety of prescription and over-the-counter medications. 5 Clinical Toxicology 5th stage Weaam J. Abbas  Toxidrome and clinical manifestations Signs and symptoms: Clinical manifestations are caused by: CNS effects Peripheral nervous system effects Or both 6  Toxidrome and clinical manifestations Clinical manifestations may include:  Flushing  Dry skin and mucous membranes  Mydriasis with loss of accommodation  Altered mental status  Fever 7 Clinical Toxicology 5th stage Al-Mustaqbal University / College of Pharmacy Weaam J. Abbas  Toxidrome and clinical manifestations Additional manifestations include the following:  Sinus tachycardia  Decreased bowel sounds  Urinary retention  Hypertension 8 Clinical Toxicology 5th stage Al-Mustaqbal University College / Pharmacy Department Weaam J. Abbas  Anticholinergic Drugs Agents with anticholinergic properties are as follows: 1. Anticholinergics  Atropine scopolamine 2. Antihistamines  Chlorpheniramine  Cyproheptadine  Diphenhydramine  Promethazine 9 Clinical Toxicology 5th stage Weaam J. Abbas  Anticholinergic Drugs Agents with anticholinergic properties are as follows: 3. Antipsychotics  Chlorpromazine  Clozapine  Thioridazine 4. Antispasmodics  Clidinium  Hyoscyamine  Propantheline 10 Clinical Toxicology 5th stage Weaam J. Abbas  Management Treatment: Initial assessment and stabilization are required Ensure an adequate airway and check that breathing is present and maintained. Assess circulation and initiate cardiac and pulse monitoring. GI decontamination with activated charcoal is recommended. Ipecac syrup is contraindicated. Ventricular arrhythmias can be treated with lidocaine. Manage seizures with benzodiazepines. 11 Clinical Toxicology 5th stage Weaam J. Abbas  Management -Antidote The antidote for anticholinergic toxicity is (Physostigmine salicylate.)  Physostigmine is the only reversible acetylcholinesterase inhibitor capable of directly antagonizing the CNS manifestations of anticholinergic toxicity. It is an uncharged tertiary amine that efficiently crosses the blood brain barrier. 12 Clinical Toxicology 5th stage Weaam J. Abbas  Management -Antidote By inhibiting acetylcholinesterase, the enzyme responsible for the hydrolysis of acetylcholine, an increased concentration of acetylcholine augments stimulation at muscarinic and nicotinic receptors. Physostigmine can reverse the central effects of coma, seizures, severe dyskinesias, hallucinations, agitation, and respiratory depression. The most common indication for physostigmine is to control agitated delirium. Physostigmine is contraindicated in patients with cardiac conduction disturbances (prolonged PR and QRS intervals) on ECG analysis. 13 Clinical Toxicology 5th stage Weaam J. Abbas