Autonomic Nervous System - week 4

Week 4

what are the 2 parasympathetic receptors?

muscarinic and nicotinic

does mascarinic or nicotinic affect skeletal muscle ?

nicotinic

what is the role of muscarinic?

stimulate smooth muscle and slow HR (rest and digest)

what classes of drugs work on the PNS?

cholinergics and anticholinergics

what are the 4 different receptors for the SNS?

alpha 1, alpha 2, beta 1 beta 2

what does the alpha 1 receptors affect?

peripheral blood vessels, pupils and bladder are affected by this receptor

what does beta 1 receptors affect?

they affect the heart and the kidneys

what is the role of alpha 2 receptors ?

they inhibit the neurotransmitter release

what does beta 2 receptors affect?

they affect the smooth muscle (found inside all hollow organs - BV, GI, GU etc), uterus and resp tract

what are the drug classes that work on the SNS called?

adrenergic agonists/antagonists and beta agonists/blockers

is NE the pre or post-ganglionic neutrotransmitter?

post-ganglionic

what is the role of alpha 2 receptors when they are activated?

to inhibit neurotransmitter release

If NE binds to either of the alpha 2 or beta 2 receptors, does it stimulate or inhibit the beta receptors actions?

inhibits the actions

If NE binds to either of the alpha 1 receptors or beta 1 receptors, does it stimulate or inhibit the beta receptors actions?

stimulate

how to ANS drugs work? (where)

ANS drugs work because they act at synapse where they

• stop the production of neurotransmitters

• stop neurotransmitters from being stored in vesicles

• influence the release of neurotransmitters

• bind to the receptor sites, leading the the neurotransmitters not being able to bind

• stops the uptake of the neurotransmitters

when are cholinergic medications used?

glaucomas (they cause pupil constriction), urinary retention, to decrease BP, increase digestion, BPH, neurogenic bladder, myasthenia gravis, alzheimers

what are the s/s of cholinergic toxicity?

salivation, lacrimation, urinary incontinence, diarrhea, gastroinestinal cramps, emesis

what drug is used as an antidote for anticholinergic poisoning?

physostigmine

when should you use caution with giving anticholinergics?

geriatric population, especially if they have BPH and urinary retention

what are some side effects of anticholinergic medications?

photophobia, dry mouth/difficulty swallowing, blurred vision, agitation

should a pt be on a high fibre and fluids diet if they are on anticholinergics or cholinergic medication?

anticholinergic meds

higher risk for heat stroke is a consideration for anticholinergic or cholinergic medications

anticholinergic medications

what is the role of dobutamine?

increase contractility an elevate BP

what is the role of phenlyephrine?

causes vascular constriction in nasal arteries, dries up nasal drip and mucous

what is the role of atenolol?

slows HR and drops BP

T/F: you can give adrenergic medications to pt who have CAD and/or MI

false - they increase the demand for oxygen on the heart

why should you avoid caffeine when on adrenergic medications?

they both end up stimulating the ‘fight or flight’ response, so you end up with an additive effect

T/F headache, tremors, nervousness and palpitations are all common when on adrenergic medications and there is no need to call HCP

False: tremors and headaches are normal, but nervousness and palpitations should be reported to HCP

what are the contraindications of adrenergic agonists?

narrow-angle glaucoma, tachycardia, arrhythmias, HTN, liver disease, enlarged heart, vein or artery disorders, disorders that affect the blood supply to the brain

what are the contraindications of cholinergic agonists?

GI or GU tract obstruction, bradycardia, epilepsy, hypotension, COPD, parkinson’s disease