autonomic nervous system: parasympathetic division

what are the effects of the parasympathetic division

slows heart, respiratory rate, lowers BP

stimulates digestive and urinary systems

warms the skin

miosis

natural parasympathetic neurotransmitter

acetylcholine, synapses with cholinergic receptors

types of cholinergic receptors

nicotinic and muscarinic

nicotinic receptors

essential for skeletal muscle control (including the diaphragm)

muscarinic receptors

Cholinergic receptors that are located postsynaptically in the effector organs such as smooth muscle (lung bronchioles, GI tract, bladder), and cardiac muscle

typical muscarinic response (DUMBELS)

Defecation/diarrhea

Urination

Miosis (pupil constriction)

Bradycardia

Bronchospasm

Bronchorrea

Blood pressure decrease

Emesis

Lacrimation

Salivation/secretions (GI and lungs)

bronchorrea

excessive discharge of mucus from the bronchi

direct acting cholinergic drugs

Bind directly to cholinergic (mostly muscarinic) receptors to produce effects that mimic Ach

indirect acting cholinergic drugs

Inhibit the action of AchE (an enzyme that breaks down ach) which increases the amount of Ach at the receptor

Direct acting cholinergic drugs include

bethanochol and pilocarpine

bethanechol

treats urinary retention and allows one to void

bethanechol mechanism of action

directly interacts with muscarinic receptors to cause parasympathetic stimulation

adverse effects of bethanechol

profuse salivation, sweating, increased muscle tone, urinary frequency, bradycardia, hypotension, exacerbation of asthma

contraindications to bethanechol

-Asthma/COPD

nursing considerations for bethanechol

monitor u/o and I/O, as well as HR and BP, give on an empty stomach

pilocarpine

treats xerostomia (oral) and glaucoma (eye drops)

xerostomia

dryness of the mouth or eyes

Pilocarpine mechanism of action

muscarinic agonist that induces secretions (GI, salivation, sweating)

adverse effects of pilocarpine

cholinergic crisis (DUMBELS)

Indirect-Acting Cholinergic Agonists include

pyridostigmine

pyridostigmine

treats myasthenia gravis, alzheimer's disease, reverse anticholinergic effects, reverses effects of neuromuscular blocking agents, treating nerve gas

pyridostigmine mechanism of action

inhibits acetylcholinesterase, thereby increasing acetylcholine's activity in the parasympathetic system

pyridostigmine adverse effects

DUMBELS, decreases in BP and HR, cholinergic crisis

pyridostigmine nursing considerations

beware unintended outcomes such as cholinergic crisis

Organophophates/Carbamates

includes insecticides (malathion) and nerve gas (V agents like VX sarin)

Organophophates/Carbamates mechanism of action

acetylcholinesterase inhibitors that may irreversible, can cause cholinergic crisis

cholinergic crisis

severe muscle weakness and respiratory paralysis due to excessive acetylcholine, treated with cholinergic blocking drug

anticholinergic/cholinergic blocking drugs include

Atropine, scopolamine, oxybutynin, solifenacin, tolterodine

atropine

antidote to poisoning by cholinergic drugs, reduces salivation and secretions, used in the OR to reduce secretions, ACLS

symptomatic bradycardia

atropine blocks the vagus nerve's influence of the heart, relieving bradycardia

Atropine mechanism of action

antagonist at various muscarinic receptors in the parasympathetic division, allowing sympathetic division to take control of the heart

atropine adverse effects

tachycardia, CNS stimulation, salivation, constipation, urinary retention, dry eyes, decreased sweating

Atropine Contraindications

glaucoma, BPH, urinary retention, hesitancy

Atropine nursing considerations

geriatric populations more likely to develop adverse effects

scapolamine

treats motion sickness, post-op nausea/vomitting, pre-op oversalivation

scapolamine mechanism of action

blocks Ach receptors in the vestibular nuclei and reticular formation

scapolamine contraindications

narrow angle glaucoma, BPH

nursing considerations for scapolamine

apply at least 4 hours to travel, changing the patch every 3 days, rotate the areas to decrease skin irritation, dont cover the patch

Oxybutynin, solifenacin, tolterodine

treats overactive bladder, urinary incontinence, urgency, frequency, nocturia

Oxybutynin, solifenacin, tolterodine adverse effects

normal anticholinergic effects

Oxybutynin, solifenacin, tolterodine contraindications

glaucoma, BPH, avoid in urinary retention

Oxybutynin, solifenacin, tolterodine nursing considerations

patients should have a decrease in urinary urgency, frequency, and nocturia