Cholinergic Blocking Drugs Flashcards
What are cholinergic blocking drugs and what are they AKA?
Drugs that inhibit the action of ACh in the Parasympathetic NS
AKA: Anticholinergics, parasympatholytic drugs, antimuscarinic drugs
What is the MOA of cholinergic blocking drugs?
Competitive antagonist
They compete with ACh for binding at muscarinic receptors
Name 2 Natural plant alkaloids
Atropine sulphate
Scopolamine hydrobromide
Name 3 synthetic and semisynthetic anticholinergics
Glycopyrrolate
Oxybutynin
Tolterodine
What are CNS and Cardiovascular drug effects in small and large doses?
CV
Small doses: Decreased HR
Large doses: Increased HR
CNS
Small doses: Decreased muscle rigidity and tremors
Large doses: Drowsiness, disorientation, hallucinations
What are the eye and GI drug effects?
Eye: Dilated pupils, Decreased accomodation caused by paralysis of ciliary muscles
GI: Relaxed muscle tone, Decreased secretions, motility and peristalsis
What are the GU, Glandular and Respiratory drug effects?
GU: Relaxed detrusor, increased constriction of internal sphincter resulting in urinary retention
Glandular: Decreased sweating
Resp: Decreased bronchial secretions
What are the CNS indications of anticholinergics?
Decreasing muscle rigidity and muscle tremors
Parkinson’s
Drug-induced extrapyramidal reactions
What are the cardiovascular indications of anticholinergics?
Affect the hearts conduction system
Low doses: Decreased HR
High: Block inhibitory vagal effects on SA and AV node pacemaker cells resulting in increased HR
Atropine is used primarily for cardiovascular disorders such as:
Diagnosis of sinus node dysfunction
Symptomatic second-degree heart block
Severe sinus bradycardia with hemodynamic compromise
What are the respiratory indications of anticholinergics?
Exercise-induced bronchospasms
Asthma
COPD
What are the GI indications of anticholinergics?
IBD
GI hypersecretory states
What are the GU indications of anticholinergics?
Reflex neurogenic bladder
Incontinence
What are the contraindications of Anticholinergics?
Angle-closure glaucoma
Acute asthma or other resp distress
Myasthenia gravis
Acute cardiovascular instability
GI or GU tract obstruction
What are the cardiovascular and CNS adverse effects?
Cardio: Increased HR, Dysrhythmias
CNS: Excitation, restlessness, irritability, disorientation, hallucinations, delirium
What are the Eye and GI adverse effects?
Eye: Dilated pupils, increased intraocular pressure
GI: Decreased salivation, gastric secretions and motility resulting in constipation
What are the GU, Glandular and resp adverse effects?
GU: Urinary retention
Glandular: decreased sweating
RESP: decreased secretions
What are the treatments of anticholinergic toxicity/ OD?
Continuous ECG monitoring
Activated charcoal
Treatment of shock
Physostigmine (cholinergic)
What are the possible interactions with anticholinergics?
Amantadine
Antihistamines
Phenothiazines
Digoxin
What is atropine? (ID, CI)
ID: Brady, ventricular asystole, antidote for cholinergic toxicity, pre-op to decrease salivation and GI secretions
CI: Angle-closure glaucoma, renal and hepatic dysfunction, hiatal hernia, intestinal atony, GI or GU obstructions, ulcerative colitis
What is Glycopyrrolate? (ID, MOA)
MOA: Blocks receptor sites in the autonomic nervous system that control prod of secretions
ID: Pre-op to reduce salivation and secretions in resp and GI
What is oxybutynin? (ID, CI)
ID: Overactive bladder and antispasmodic for neurogenic bladder associated with spinal cord injuries
CI: Urinary or gastric retention, angle-closure glaucoma
What is Scopolamine? (ID, AE, IE)
ID: Prevention of motion sickness, prevention of post-op N/V
AE: Drowiness, dry mouth, blurred vision
IE: CNS depressants or alcohol results in increased sedation
What is Tolterodine? (ID)
ID: Urinary freq, urgency and urge incontinence caused by bladder over-activity
