Nursing Pharm w3 content

Sympathetic Nervous system Functions

maintain blood flow to the brain

redistribute blood flow during exercise

compensate for blood loss via vasoconstriction

Regulating body temperature

ex. increase HR, increase BP, decrease GI motility, dilation of the bronchi, dilation of the pupils

Parasympathetic Nervous system

slowing HR

increasing GI secretions

pupil constricition

emptying the bowels and bladder

contracting smooth bronchial muscle

PNS Transmitters

Acetylcholine

Norepinephrine

epinephrine

Acetylcholine

all preganglionic nuerons of the PNS have this

all postganglionic neurons have this in the PNS

all motor neurons to skeletal muscles have this

Norephinephrine

all postganlionic neurons of the SNS have this transmitter except sweat glands

Epinephrine

released by the adrenal medulla

cholinergic receptors

mediate the response of acetylcholine

Adrenergic recpetors

mediatate the response to EP and NorEP

Cholinergic subtypes

NicotinicN, NicotinicM, and Muscarinic

Adrenergic subtype

Alpha1, Alpha2, Beta1, and Beta2

Dopamine

receptor drug subtypes are,,,

important to drug selectivity

PNS

brain—> Preg neuron—> Ach, Nn—> postg neuron—> Ach M

SNS with alpha and beta

brain—→preg nueron—> ach—→Nn—→postg, NE alpha or beta

sweat glands

ACH, NN, ACH, M

SNS adrenal Medulla alpha or beta

ACH, NN, EPI

Skeletal muscle

no pre or post g, ACH, NM

NN receptors

NicotinicN Receptors

Promote ganglionic transmission at all ganglia of the sympathetic and parasympathetic nervous system.

Promote release of epinephrine from the adrenal medulla

NicotinicM Receptor

Causes skeletal muscle contraction

Muscarinic Receptor

Elicits responses from the target organ – i.e. glandular secretion, contraction of smooth muscle, decreased
HR, pupillary constriction,

alpha 1 receptors

Located in the eye, blood vessels, male sex organs, prostatic capsule and bladder
Causes contraction of the radial muscle of the eye (pupillary dilation), constriction of veins and arterioles, contraction
of the prostatic capsule and bladder trigone and sphincter and ejaculation

alpha 2 receptors

Drug effects from stimulation of peripheral nervous system Alpha2 receptors are of minimal significance.

Beta1 Receptors

Located in the heart and the kidneys.
• Activation of Beta1 cardiac receptors has an important therapeutic response to increase HR, force of contraction, and velocity of impulse
conduction.
• Activation of Beta1 receptors in the kidneys stimulates the release of renin

Beta2 Receptors

Located in the heart, lungs, skeletal muscle, bronchi, uterus, liver.
• Activation in the lungs facilitates bronchial dilation, uterine activation causes uterine smooth muscle relaxation. Effects of activation on
arterioles of the heart, lungs, and skeletal muscle is vasodilation – the opposite effect of what we see with alpha1 activation

Dopamine Receptors

• The only clinically significant dopamine receptors are located in the kidneys where activation causes dilation of renal
blood vessels and improve renal perfusion.

Bethanechol (Urecholine, Duvoid)

Muscarinic cholinergic agonist

Bethanechol (Urecholine, Duvoid

MOA:Direct-acting muscarinic agonist that binds reversibly to
muscarinic cholinergic receptors. Selective activation on muscarinic receptors.

Bethanechol (Urecholine, Duvoid

used for urinary retention and off label use for GERD and dysmobility disorders of the GI tract

ADEs of Bethencol

Cardiovascular – Bradycardia and hypotension (2/2 vasodilation)
 GI – Excessive salivation, increased gastric acid, abdominal cramps, diarrhea
 Urinary Tract – Increases bladder pressure, could cause bladder rupture if there is obstruction
or weakness of the bladder wall.
 Pulmonary – Bronchoconstriction – CONTRAINDICATED for asthmatic patients.
 Dysrhythmias – Dysrhythmias and tachycardia only in those with hyperthyroid –
CONTRAINDICATED for patients with hyperthyroidism.

Cevimeline (muscarinic agonist)

used for dry mouth

used in patients with autoimmune disorder that causes attack on the salivary gland cells

moa - increases salvation

Pilocarpine (muscarinic Agonist)

for glaucoma

moa: pupillary constriction of the iris sphincter which causes contraction of the detrusor muscles

decreases intraocular pressure

Acetylcholine (muscarinic agonist)

pupillary constriction

used after cardiac surgery

Atropine M antagonist

Classification: Anticholinergic
Mechanism of Action: Competitive blockade at muscarinic receptors; has no
direct effect on its own all responses are a result of preventing muscarinic
receptor activation

Atropine (M antagonist)

Therapeutic Uses: Pre-anesthetic medication, eye disorders, symptomatic
bradycardia, intestinal hypermotility, and muscarinic agonist poisoning.

Atropine ADEs

Xerostomia (dry mouth), blurred vision and photophobia, elevation of intraocular
pressure, urinary retention, constipation, anhidrosis (decreased sweating),
tachycardia

Scopolamine ( M antagonist)

o Similar to atropine with 2 important exceptions:
1. Can produce CNS sedation at therapeutic doses.
2. Suppresses emesis and motion sickness.

Ipratropium bromide (Atrovent) ( M antagonist)

o Muscarinic antagonism results in bronchial dilation
o Therapeutic uses include asthma, COPD, and rhinitis

icyclomine (Bentyl) ( M antagonist)

o Muscarinic antagonism results in decreased intestinal tone and motility
o IBS, functional bowel disorders

Another M antagonist

Urinary Antispasmodics
o Anticholinergic medications used to treat overactive bladder.

Oxybutynin (Ditropan,
Oxytrol) Anticholinergic, urinary antispasmodic agent

Mechanism of Action: Acts primarily on muscarinic M3 subtype receptors.
Therapeutic Uses: Only approved for treatment of OAB
Routes: PO (long & short-acting), transdermal patch, topical gel

Oxybutynin (Ditropan,
Oxytrol) ADEs

Dry mouth, constipation, tachycardia, urinary retention, mydriasis, blurred vision, and dry eyes. Can
also see CNS effects – sedation, hallucinations and confusion