Nervous System Flashcards
Alpha Adrenergic Agonists
Epinephrine, Norepinephrine, ephedrine, phenylephrine
Indication: Cardiac arrest, shock, hypotension, control bleeding anaphylaxis | nasal decongestant
Action: Activates the alpha receptors of the sympathetic nervous system → FIGHT OR FLIGHT
Results in: vasoconstriction, pupil constriction
Nursing Considerations:
● Adverse effects:
○ Hypertension, tachycardia angina, hyperglycemia, necrosis is drug extravasates
● Drug interactions
○ MAOIs
○ TCAs
○ Alpha or beta blockers
● Ephedrine/Phenylephrine - local effects of vasoconstriction used in nasal sprays for congestion
Alpha Adrenergic Antagonists
Prazosin, Doxazosin, Terazosin, Tamsulosin, Alfuzosin, Silodosin, Phentolamine
Indication: Hypertension, BPH, Raynaud’s disease, pheochromocytoma
Action: Blocks activation of alpha receptors in the sympathetic nervous system - stops fight or flight
resulting in: vasodilation, decreased BP
Nursing Considerations:
● Adverse effects: hypotension, reflex tachycardia, nasal congestion
○ First dose effect: significant orthostatic hypotension with first dose. Take at bedtime!
● Not safe in children, pregnancy, or breastfeeding
Beta Adrenergic Agonists - Non-selective
Propranolol, nadolol, pindolol, sotalol, timolol
Indication: HTN, angina, dysrhythmias, MI
Action: Blocks activation of beta ONE and TWO receptors in the sympathetic nervous system -
stops fight or flight resulting in: decreased HR, decreased force of contraction, suppression of
impulse conduction through the AV node (𝛃-1) AND bronchoconstriction, decreased
gluconeogenesis (𝛃-2)
Nursing Considerations:
● Adverse effects:
○ Bradycardia → Avoid if client is in SB or has an AV block
○ HF → Avoid in clients with HR (it decreases the CO!)
○ Bronchoconstriction → Extreme caution in asthmatics!
○ Hypoglycemia → Caution in diabetics! Warn them will mask typical symptoms of hypoglycemia!
○ Rebound cardiac excitation → never discontinue abruptly - taper off!
○ Depression → Caution in clients with mental health conditions
● Caution in clients with life threatening allergies (if on a BB, epi will be less effective if they have a reaction)
Beta Adrenergic Antagonists - Selective
Metoprolol, Acebutolol, Atenolol, Betaxolol, Bisoprolol, Esmolol, carvedilol, labetalol
Indication: HRN, angina, HF, MI
Action: Blocks activation of beta ONE receptors in the sympathetic nervous system - stops fight or
flight resulting in: decreased HR, decreased force of contraction, suppression of impulse conduction
through the AV node
Nursing Considerations:
● Adverse effects:
○ Bradycardia → Avoid if client is in SB or has an AV block
○ Rebound cardiac excitation → never discontinue abruptly - taper off!
● *Safer for asthma! No 𝛃-2 action = no bronchoconstriction
● *Safer for diabetics! No 𝛃-2 action = no hypoglycemia
Cholinergics
Muscarinic Agonists: Bethanechol, Cevimeline, Pilocarpine
Cholinesterase Inhibitors: Pyridostigmine, neostigmine, physostigmine, edrophonium, rivastigmine
Indication: Urinary retention, GERD, MG, Alzheimer’s, Glaucoma
Action: The neurotransmitter of the parasympathetic nervous system is acetylcholine. Cholinergic
drugs stimulate cholinergic receptors or increase acetylcholine and therefore cause REST AND
DIGEST: Increase GI secretions and motility, increase urination and urinary function, pupil
constriction (miosis), decrease HR
Nursing Considerations:
● Monitor for cholinergic side effects: increased secretions, increased urination, miosis, etc.
● Monitor for bradycardia
● Contraindications: Intestinal obstruction, urinary tract obstruction, asthma, hyperthyroidism, hypotension
● Education: take on an empty stomach
Muscarinic Poisoning
TOO many muscarinic receptors are activated OR too many cholinesterase
inhibitors are breaking down cholinesterase…. Causing TOO MUCH acetylcholine.
TOO MUCH rest and digest!
Causes:
● Medication OD
● Toxic mushrooms
Treatment: Atropine
Anticholinergics
Muscarinic Antagonists: Atropine, scopolamine, ipratropium bromide, dicyclomine, oxybutynin, tolterodine
Indication: Sinus bradycardia, AV block, eye exams, asthma, excessive secretions, intestinal
hypertonicity, overactive bladder
Action: Block acetylcholine in the parasympathetic nervous system thereby blocking REST AND
DIGEST functions. Causes: increased HR, pupil dilation, bronchodilation, decreased secretions,
sweating, GI motility, urinary retention
Nursing Considerations:
● Adverse effects:
○ Increased IOP (→blurry vision/photophobia) - avoid in glaucoma!
○ Urinary retention → caution in BPH
○ Bronchial plugging → caution in asthma
○ Constipation, xerostomia, tachycardia, anhidrosis
● Contraindication: MG, glaucoma, urinary or intestinal obstruction, tachycardia
Anticholinergic toxicity
Activated charcoal
○ Decrease absorption of the drug
● Physostigmine
○ Antidote
○ Cholinergic drug
Hot as a hare
Dry as a bone
Red as a beet
Blind as a bat
Mad as a hatter
Central Nervous System Drugs
Anti-Parkinson Drugs
○ Levodopa
○ Levodopa/Carbidopa
● Drugs for memory
○ Cholinesterase inhibitors
● Anticonvulsants
○ Long-term
○ Rapid acting
● Drugs for spasticity/spasms
Anti-Parkinson Drugs
Names: Levodopa, Levodopa/Carbidopa
Carbidopa inhibits the breakdown of levodopa so it lasts longer!
Indication: Parkinson’s disease
Action: Increases dopamine synthesis resulting in more dopamine, and less motor
symptoms in parkinson’s disease.
Nursing Considerations:
● Full therapeutic response takes a few months to develop
● Beneficial effects wear off over time
● Side effect: nausea/vomiting. Take with low-fat, low protein foods.
● Can cause postural hypotension/dizziness - move slowly when changing positions
● Adverse effect: psychosis (visual hallucinations, vivid dreams, paranoid ideation)
Cholinesterase inhibitors
Names: Donepezil, rivastigmine, galantamine
Indication: Alzheimer’s, Dementia
Action: Prevent breakdown of acetylcholine; increasing its’ bioavailability which results in
better transmission in central cholinergic neurons. Causes improved memory, thought, and
reasoning.
Nursing Considerations:
● These medications do not cure AD or stop it’s progression - they improve symptoms in
mild to moderate AD
● Cholinergic side effects, bronchoconstriction*, CV effects (bradycardia)
● *Caution in clients with asthma or COPD
Anticonvulsants - Long Term
Names: Phenytoin, fosphenytoin, carbamazepine, phenobarbital, valproic acid
Indication: Seizures
Action: Selectively inhibits sodium channels, suppressing action potentials in hyperactive
neurons. Stops the ‘seizure-generating neurons’ activity - while leaving healthy neurons
alone!
Nursing Considerations:
● Phenytoin therapeutic level: 10-20 mcg/mL
● Side effect: gingival hyperplasia → Regular dental check-ups + Use soft bristle toothbrush
● Antacids can reduce the effect of phenytoin and should be avoided
● Serious pregnancy effects
○ Phenytoin is a known teratogen
● Interact with many drugs
○ No alcohol/other CNS depressants
○ Consult with HCP
Anticonvulsants - Rapid Acting/Emergent
Names: Lorazepam, diazepam
Indication: Seizures
Action: CNS depression
Nursing Considerations:
● Monitor for respiratory depression
● Antidote - flumazenil
Muscle Relaxer
Names: Baclofen, dantrolene, cyclobenzaprine, chlorzoxazone, tizanidine
Indication: Spasticity, spasms (MS, SCI)
Action: Suppresses hyperactive reflexes in the spinal cord - decreasing spasms
and resistance to passive movement
Nursing Considerations:
● CNS side effects: drowsiness, dizziness, weakness, fatigue
○ Serious hypotension can occur!
○ Avoid alcohol or other CNS depressants
● Do not discontinue abruptly
