Atropine's anti muscarinic effects:
Anticholinergic properties jimson weed and Atropine poisoning similarities:
jimson Weed (Datura stramonium) poisoning -This condition is also called as "Gardener's mydriasis" jimson Weed produce toxins (belladonna alkaloids) that possess strong anticholinergic properties jimson weed and atropine poisoning are strikingly similar. Blockade of visceral muscarinic receptors produces the following effects
1 Heart -diminished vagal tone at the SA node causes relative tachycardia
2 Blood vessels- vasoconstriction via muscarinic receptor blockade in endothelial cells results in decreased nitric oxide synthesis In spite of this effect, atropine poisoning is associated with cutaneous flushing: the pathogenesis of this effect is unknown
3 GI- delayed gastric emptying, decreased intestinal motility, and secretion 4 Respiratory bronchodilatation
5 GU- urinary retention vi a detrusor relaxation and contraction of the external urethral sphincter
6 Secretions decreased lacrimation (dry eyes), salivation (dry mouth) and sweating (dry and hot skin) Atropine decreases one's ability to sweat, contributing to hyperthermia
7 Eye- mydriasis (dilated pupils) and cycloplegia (inability to focus on the near objects, blurry vision)
8 CNS -hallucinations, agitation and delirium
Atropine's anti muscarinic effects can be counteracted by increasing the concentration of acetylcholine in the synaptic cleft increased acetylcholine concentrations are produced by cholinesterase inhibitors that suppress acetylcholine degradation Physostigmine, a cholinesterase inhibitor, can be used for treatment of atropine overdose
0 comments
Post a Comment