Cholinergic Drugs Flashcards
What do cholinergic drugs stimulate?
Parasympathetic nervous system
Nicotinic Receptors
Located in the ganglia of PSNS and SNS
We want to decrease nicotinic reactions
Muscarinic Receptors
Located postsynaptically in the effector organs of PSNS
We want to increase muscarinic reactions
Cholinergic Drug Effects
Stimulate intestine and bladder Stimulate pupils Increase salivation and sweating Decrease cardiovascular effects Narrow airways
Cholinergic Doses
At recommended doses, cholinergics affect muscarinic receptors.
At high doses, cholinergics stimulate nicotinic receptors (causes undesirable effects)
Indirect-Acting Drugs
Used for diagnosis and treatment of myasthenia gravis
Used to reverse neuromuscular blocking drugs
Cause skeletal muscle contractions
Contraindications of Cholinergic Drugs
Known drug allergy, GI obstruction, bradycardia, hyperthyroidism, epilepsy, hypotension, COPD, Parkinson’s
Adverse Effects
Bradycardia, hypotension, syncope, dizziness, increased secretions, abdominal cramps, bronchospasms
Cholinergic Crisis
Circulatory collapse, hypotension, bloody diarrhea, shock, cardiac arrest
SLUDGE
Early signs include abdominal cramps, salivation, skin flushing, nausea, transient syncope, transient complete heart block, dyspnea, orthostatic hypotension
Treatment of Cholinergic Crisis
Early phase: atropine
Severe: epinephrine
Bethanechol (Urecholine)
Direct-acting cholinergic agonist
Used to help patients urinate again if they have nonobstructive urinary retention
Adverse Effects of Bethanechol
Syncope, hypotension with reflex tachycardia, headache, seizure, GI upset, asthma attacks
Interactions of Bethanechol
Acetylcholinesterase inhibitors (indirect-acting cholinergics)
Donepezil (Aricept)
Cholinesterase inhibitor that increases ACh by inhibiting acetylcholinesterase
Used in treatment of mild to moderate Alzheimer’s
Does not cure the disease
Adverse Effects of Donepezil
GI upset, drowsiness, dizziness, insomnia, muscle cramps, bradycardia, syncope, hypertension, hypotension
Interactions of Donepezil
Anticholinergics and NSAIDs
Pyridostigmine (Mestinone)
Used to treat myasthenia gravis by increasing ACh and inhibiting acetylcholinesterase
Edrophonium (Tensilon)
Used to diagnose myasthenia gravis
Helps differentiate between myasthenia gravis and cholinergic crisis
Tensilon test: give IV push Tensilon, patient’s symptoms disappear for a short period of time
Nursing Implications
Assess for presence of GI obstructions
Do not stop abruptly
Encourage patients with myasthenia gravis to take medication 30 minutes before eating
Teach that therapeutic effects of anti-Alzheimer’s drugs may not occur for up to 6 weeks
Atropine is the antidote for cholinergics
