1 / 15

Cholinoceptor Blocking Agents

Cholinoceptor Blocking Agents. Pawitra Pulbutr M.Sc. In Pharm (Pharmacology). Objectives. นิสิตมีความรู้ความเข้าใจถึงเภสัชวิทยา กลไกการออกฤทธิ์ เภสัชจลนศาสตร์ การใช้ประโยชน์ทางคลินิก อาการไม่พึงประสงค์ ข้อควรระวังการใช้ยาของที่ออกฤทธิ์ต้านโคลิโนเซปเตอร์. Cholinoceptor Blocking Agents.

isaura
Télécharger la présentation

Cholinoceptor Blocking Agents

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cholinoceptor Blocking Agents Pawitra Pulbutr M.Sc. In Pharm (Pharmacology)

  2. Objectives • นิสิตมีความรู้ความเข้าใจถึงเภสัชวิทยา กลไกการออกฤทธิ์ เภสัชจลนศาสตร์ การใช้ประโยชน์ทางคลินิก อาการไม่พึงประสงค์ ข้อควรระวังการใช้ยาของที่ออกฤทธิ์ต้านโคลิโนเซปเตอร์

  3. Cholinoceptor Blocking Agents • Inhibit binding of ACh or cholinoceptor agonist to cholinoceptor • Cholinoceptor antagonist/ blocker • Parasympatholytic … Not appropriate • Antimuscarinic receptor • Antinicotinic receptor • Ganglionic blocker • Neuromuscular blocker

  4. Basic Pharmacology of Muscarinic blocker • Prototype = “Atropine” • Tertiary amine derivative • Quaternary amine derivative … increase peripheral effect • Atropine (Hyoscyamine) • Atropa belladonna (deadly nightshade) • Datura stramonium (jimsonweed or thorn apple) • L (-) hyoscyamine = natural occur • d,l- hyoscyamine = commercial available • Scopolamine (Hyoscine) • Hyoscyamus niger • L (-) hyoscine = natural occur • L-isomer is more active than d-isomer

  5. Organ System Effects • CNS • Atropine • CNS stimulation…also sedative effect • Scopolamine … More CNS effect • Drowsiness, amnesia • Toxic dose … excitement, agitation, hallucination, coma • Use • Tremor in Parkinson’s disease • Overcholinergic activity… Too much ACh • Lack of dopaminergic activity in brain • Antimuscarinic agent + Dopamine precursor • Motion sickness … Vestibular disturbance • Scopolamine

  6. Eyes • Cholinoceptor … Control pupillary contractor muscle & ciliary muscle • Anticholinoceptor • Mydriasis • Inhibit ciliary muscle contraction • Cycloplegia • Focus defect • Use in ophthalmology • Caution in glaucoma… increase intraocular pressure • Decrease lacrimal secretion, sandy eyes

  7. CVS • Atropine at heart • Low dose… Inhibit presynaptic cholinoceptor first … increase ACh release …bradycardia • Moderate to high dose… Relative tachycardia • AV node • (+) dromotropic … Shorten PR interval • Less effect on ventricle • Total effect of Atropine • >>> Modest effect in normal hemodynamic • Tachycardia • Less effect on BP

  8. Respiratory system • Vagal innervation … Smooth muscle & secretory gland • Atropine • Bronchodilation • Decrease secretion • Use • Asthma… less effective than 2-agonist • Chronic Obstruction Pulmonary Disease (COPD) • Premedication of inhalant anesthetic agent… decrease secretion & laryngospasm

  9. GI tract • Decrease GI motility & secretion • Prolong gastric emptying time & intestinal transit time • Partially effect …ENS controlled by local hormone & other noncholinergic neuron • Decrease saliva …dry mouth • Less effect on gastric secretion • Mostly on basal secretion • Pirenzepine, Telezepine… decrease gastric acid secretion • No effect on pancreatic & intestinal secretion … under hormonal control • Use • Peptic ulcer… Not use recently • Control diarrhea from parasympathetic system overactive • Spasmolytic action

  10. Genitourinary tract • Relaxation of ureter & bladder • Decrease voiding • Use …urinary tract spasm… inflammation • Caution in elderly male … BPH>>> urinary retention • No effect on uterus

  11. Sweat gland • Inhibit thermoregulatory sweating • Inhibit eccrine gland secretion • Controlled by cholinergic sympathetic nerve • May cause …Atropine fever

  12. Clinical Pharmacology • Parkinson’s disease • Motion sickness • Mydriasis • Adjunct to general anesthesia • Asthma/ COPD • Hyperactive carotid sinus reflex … fainting • Antispasmodic, traveller diarrhea, peptic ulcer • Urinary urgency • Urolithiasis • Cholinergic poisoning

  13. ADRs of anticholinoceptor • Depends on desired effect • Cholinoceptor blocking effect • Dry mouth, mydriasis, tachycardia, hot flush, agitation, delirium, increase body temperature (esp infant) • Reversal of atropine overdosage • Symptomatic • ACh E inhibitor … physostigmine … ADRs

  14. Contraindication of Atropine • Glaucoma • Angle closure glaucoma • Elderly male • BPH • Peptic ulcer • Decrease gastric emptying

  15. Q & A

More Related