Parasympathetic NS Flashcards
What two categories do PSNS drugs fall into?
- Parasympathomimetic
2. PSNS Blockers
What two sub groups do Parasympathomimetics breakdown into?
- Acetylcholinesterase inhibitors
2. Pure muscarinic agonists
Name two Acetylesterase inhibitors?
- Neostigmine
2. Malathion
Name one pure muscarinic agonist?
- Pilocarpine
What category of PSNS drugs are muscarinic antagonists?
PSNS Blockers
What is the MOA of Neostigmine?
- Indirectly and reversibly increases Ach levels by inhibiting Ach-esterase
- Stimulates muscarinic receptors
- Miosis (pupil constriction)
- Increases peristalsis and bladder voiding
- Slows heart rate
- Bronchoconstriction
What is the therapeutic use of Neostigmine?
- Diagnosis of myasthenia gravis (Edrophonium)
- Alzheimer’s treatment (Rivastigmine)
What are the adverse effects / contra-indications of Neostigmine?
- Asthma
- Bradycardia
- Diarrhea
- Salivation
What is the MOA of Malathion?
- Indirectly and irreversibly increases Ach levels by inhibiting Ach-esterase.
- All post-ganglionic muscarinic receptors in GIT and bronchial muscles stimulated
- Miosis (pupil constriction)
- Increases peristalsis, mucous production and bladder voiding
- Slows heart rate
- Bronchoconstriction
What is the therapeutic use of Malathion?
- HIGHLY toxic pesticide
antidote = atropine
What are the adverse effects / contra-indications of Malathion?
- Patients drown in own secretions (salivation and mucous production)
- Bradycardia
- Asthma
- Diarrhea
What is the MOA of Pilocarpine?
- Stimulates muscarinic receptors
- Miosis
- Opens trabecular network in the canal of Schlemm (fluid can leave eye)
What is the therapeutic use of Pilocarpine?
- Allows aqueous humour outflow from eye (lowers intra-occular pressure)
- Used in conjuction with other preparations
- Glaucoma
What are the adverse effects / contra-indications of Pilocarpine?
- Asthma
- Diarrhea
- Bradycardia
- Salivation
Name three muscarinic antagonists?
- Atropine
- Hyasine
- Ipratropium (bromide)
What is the MOA of Atropine?
- Blocks post-ganglionic muscarinic receptors
- Causes cycloplegia (paralysis of cilliary muscles - fail to accommodate for near vision)
- Decreases salivation, mydriasis (pupil dilation), salivary gland secretion and perstalsis
- Prevent bladder voiding (increases sphincter muscle tone)
- Increases heart rate
- Bronchodilation
What is the therapeutic use of Atropine?
- Antidote for organophosphate (pesticide) poisoning
- Bradycardia
- Stops vagal induced effects and decreases salivation (presurgery)
What are the adverse effects / contra-indications of Atropine?
- Blurred vision
- Dry mouth
- Tachycardia
- Constipation
- Urine retention
- Mydriasis (pupil dilation)
- Glaucoma
What is the MOA of Hyoscine?
- Blocks post-ganglionic muscarinic receptors
- Causes cycloplegia (paralysis of cilliary muscles - fail to accommodate for near vision)
- Decreases salivation, mydriasis (pupil dilation), salivary gland secretion and perstalsis
- Prevent bladder voiding (increases sphincter muscle tone)
- Increases heart rate
- Bronchodilation
What is the therapeutic use of Hyoscine?
- IBS (Irritable Bowel Syndrome)
* Doesn’t cross blood-brain barrier easily
What are the adverse effects / contra-indications of Hyoscine?
- Blurred vision
- Dry mouth
- Tachycardia
- Constipation
- Urine retention
- Mydriasis (pupil dilation)
- Glaucoma
What is the MOA of Ipratropium?
- Blocks post-ganglionic muscarinic receptors
- Causes cycloplegia (paralysis of cilliary muscles - fail to accommodate for near vision)
- Decreases salivation, mydriasis (pupil dilation), salivary gland secretion and perstalsis
- Prevent bladder voiding (increases sphincter muscle tone)
- Increases heart rate
- Bronchodilation
What is the therapeutic use of Ipratropium?
- Asthma (bronchodilator)
- COPD
- Spray/inhalant
What are the adverse effects / contra-indications of Ipratropium?
- Blurred vision
- Dry mouth
- Tachycardia
- Constipation
- Urine retention
- Mydriasis (pupil dilation)
- Glaucoma
