Cholinergic-Blocking Drugs Flashcards
Cholinergic-Blocking Drugs
Drugs that block or inhibit the actions of ACh in the PNS
Cardiovascular Drug Effects
Small doses: Decrease heart rate
Large doses: Increase heart rate
CNS Drug Effects
Small doses: Decrease muscle rigidity and tremors
Large doses: Drowsiness, disorientation, hallucinations
Eye Drug Effects
Dilated pupils (Mydriasis)
Decreases accommodation by paralysis of ciliary muscles (Cycloplegia)
GI Drug Effects
Relax smooth muscle tone
Decrease intestinal/gastric secretions
Decrease motility and peristalsis
GU Drug Effects
Relaxed detrusor muscle
Increased constriction of internal sphincter
Urinary retention
Glandular Drug Effects
Decreased bronchial secretions, salivation, and sweating
Respiratory Drug Effects
Decreased bronchial secretions
Dilated bronchial airways
CNS Indications
Decreasing muscle rigidity and muscle tremors
Parkinson’s disease
BENZTROPINE (CONGENTIN)
Cardiovascular Indications
Affects heart’s conduction system
Low doses slow the heart
High doses block inhibitory vagal effects on SA and AV nodes; results in INCREASED heart rate; ATROPINE
Respiratory Indications
Decreased secretions, relaxed smooth muscles, decreased airway resistance, bronchodilation
Used to treat bronchospasms, chronic bronchitis, asthma, and COPD
GI Indications
Used to treat IBD and GI hypersecretory states
Decreased secretions, relaxation of smooth muscle, decreased motility and peristalsis
GU Indications
Reflex neurogenic bladder
Incontinence
Contraindications
Known drug allergy Angle-closure glaucoma Acute asthma or respiratory distress Myasthenia gravis Acute cardiovascular instability GI or GU tract obstruction
Toxicity and Overdose
Symptomatic and supportive therapy Continuous ECG monitoring Activated charcoal Treatment of shock PHYSOSTIGMINE
Interactions
Amantadine, antihistamines, phenothiazines, tricyclic antidepressants, digoxin
Causes additive cholinergic effects when given with other cholinergic blocking drugs
Atropine
Used for bradycardia, ventricular asystole, antidote for anticholinesterase inhibitor toxicity or poisoning, and preoperatively to reduce salivation/secretions
Contraindicated for glaucoma, hepatic/renal dysfunction, hiatal hernia, intestinal atony, obstructive GI or GU, ulcerative colitis
Oxybutynin (Ditropan)
Synthetic antimuscarinic drug
Used for overactive bladder and antispasmodic for neurogenic bladder associated with spinal cord injuries
Contraindicated for drug allergy, urinary/gastric retention, glaucoma
Scopolamine
One of the principal belladonna alkaloids
Used to prevent motion sickness and prevent post-op nausea and vomiting
Contraindicated for glaucoma, hepatic/renal dysfunction, hiatal hernia, intestinal atony, obstructive GI or GU, ulcerative colitis
Used with CNS depressants can increase sedation
Nursing Implications
Assess for BPH, urinary retention, glaucoma, tachycardia, MI, heart failure, hernia, obstruction
Take medications exactly as prescribed
Blurred vision will cause problems with driving or operating machinery
