Autonomic Nervous System (pharm test) Flashcards
(27 cards)
Neurotransmitters
Chemical messengers that travel between neurons, stimulates the receptor site, and brings about a response
Ligands
-Neurotransmitters, hormones, and medications that can bind to receptors in the ANS
-Agonists—
-Antagonists—
-Signal transduction—cascade of intracellular events that occur when receptors located on target tissues are stimulated by a ligand
Inactivation of neurotransmitters
-By reuptake of the transmitter back into the neuron
-By enzymatic transformation or degradation
-By diffusion away from the receptors
Autonomic Nervous System: Sympathetic (Fight or Flight)
Neurotransmitters: norepinephrine, dopamine
-Increased heart rate, arterial blood pressure, and cardiac output
-Increased blood glucose
-Pupil dilation
-Increased rate of cellular metabolism
-Increased blood flow to brain, heart, and skeletal muscles
-Increased rate and depth of respiration
Autonomic Nervous System: Parasympathetic(Rest and Digest)
Neurotransmitter: acetylcholine
-Dilation of blood vessels in the skin
-Decreased heart rate
-Increased secretion of digestive enzymes
-Pupil constriction
-Contraction of smooth muscle in the urinary bladder
-Contraction of skeletal muscle
Adrenergic or Sympathomimetics
-Stimulate the sympathetic nervous system
-Effects of adrenergic agonists on receptor sites:
Alpha1 & Alpha2
Beta1 & Beta2
-Neurotransmitters (or catecholamines):
Epinephrine
Norepinephrine
Dopamine
Classification of Adrenergics/Sympathomimetics
Direct-acting sympathomimetics
-Epinephrine
-Norepinephrine
-Dopamine
Indirect-acting Sympathomimetics
-Amphetamine
Mixed-acting sympathomimetics
-Ephedrine
epinephrine: Adrenaline
-Classification: Sympathomimetic
-Action: Stimulates alpha- and beta-adrenergic receptors
-Uses:
Anaphylaxis
Bronchospasm
Cardiogenic shock, cardiac arrest
Severe asthma
-Contraindications and Caution:
Cardiac dysrhythmias, hypertension (HTN)
Hyperthyroidism
Epinephrine (cont’d)
-Adverse reactions:
-Palpitations, tachycardia, hypertension (HTN), nausea/vomiting (N/V), dyspnea, nervousness, headache (H/A), tremors, agitation & insomnia
-Life-threatening
Ventricular fibrillation, MI & pulmonary edema
-Drug interaction
-Beta-blockers
Decreases epinephrine action
-Digoxin
Causes cardiac dysrhythmias
Epinephrine: Nursing Interventions
-Monitor BP, pulse, urine output
-Report signs of adverse reaction
-Monitor IV site for infiltration
-Antidote: phentolamine mesylate (Regitine)
epinephrine (Adrenaline)
-Classification: Sympathomimetic
-Indications: Anaphylaxis, severe asthma, cardiogenic shock, cardiac arrest
-MOA: Stimulates alpha- and beta-adrenergic receptors
-Adverse Effects: Anorexia, nausea/vomiting (N/V), nervousness, headache (H/A), tremors, agitation & insomnia, palpitations, tachycardia, hypertension & dyspnea
-Life-threatening: Ventricular fibrillation, myocardial infarction (MI) & pulmonary edema
-NC: caution with cardiac dysrhythmias, hypertension (HTN), hyperthyroidism, monitor BP, pulse, urine output, report signs of adverse reaction, monitor for drug interactions with beta-blockers, digoxin
albuterol (Proventil, Ventolin)
-Classification: Beta-2 Agonist
-Mechanism of Action:
Acts on beta2-adrenergic receptors
Relaxes airway smooth muscle to promote bronchodilation
-Indications:
Treats bronchospasm, asthma, bronchitis, COPD
albuterol (Proventil, Ventolin), (cont’d)
-Caution
Severe cardiac disease, HTN, hyperthyroidism, diabetes mellitus
-Adverse Reactions
Tremors, nervousness, restlessness, dizziness & headache (H/A), tachycardia, seizures, palpitations & HTN, cardiac dysrhythmias
Nursing Interventions for albuterol
-Record VS
-Monitor ECG for dysrhythmias
-Report signs of adverse reaction (tachycardia, ↑ B/P, palpitations)
-Check urinary output- renal vasoconstriction
-Avoid doses close to bedtime.
-Check blood sugar (BS)
-Teach self administration
albuterol (Proventil, Ventolin)
-Classification: Beta-2 Agonist
-Indications: Treats bronchospasm, asthma, bronchitis, COPD
-MOA: Acts on beta2 receptors to relax airway smooth muscle to promote bronchodilation
-Adverse Reactions: Tremors, nervousness, restlessness, dizziness & headache (H/A), tachycardia, seizures, palpitations & HTN, cardiac dysrhythmias
-NC: Record VS, monitor ECG for dysrhythmias, report signs of adverse reaction (tachycardia, ↑
-B/P, palpitations), check urinary output- renal vasoconstriction, avoid doses close to bedtime, check BS, teach self administration
Beta-Adrenergic Blockers
-Uses: HTN, tachycardic dysrhythmias, angina
-Nonselective beta blockers
propranolol HCl (Inderal)
Contraindications: (COPD or asthma)
-Selective beta blockers (cardioselective)
metoprolol tartrate (Lopressor) & atenolol (Tenormin)
atenolol (Tenormin)
-Classification: Beta 1 blocker (cardioselective)
-Uses: treat HTN, angina pectoris, & MI
-Adverse Effect: drowsiness, dizziness, fainting, N/V/D, cool extremities, depression
-Adverse Reaction: bradycardia, hypotension, heart failure, dysrhythmias, pulm edema)
-Caution: renal dysfunction, asthma, COPD, diabetes mellitus
-Pregnancy category: C
-CI: sinus bradycardia, heart block > 1st degree, cardiogenic shock
atenolol (Tenormin: Nursing Interventions)
-Report AE
-Rise slowly (orthostatic hypotension)
-Monitor urine output
-Comply with med schedule (don’t suddenly stop)
-Monitor mood changes
-Monitor B/P & pulse (Pulse < 60 HOLD)
-Ask provider for parameters on BP and pulse
Cholinergics/Parasympathomimetics
-Drugs that stimulate the parasympathetic nervous system
-Muscarinic and Nicotinic receptors
-Blockage of these receptors produces anticholinergic effects
-Stimulated by acetylcholine (ACh)
Direct-Acting Cholinergic Agonists
-Selective to muscarinic receptors
-Located in smooth muscles
Heart, GI, GU, glands
metoclopramide (Reglan)
-Use: increase gastric emptying
pilocarpine (Pilocar)
-Use: constrict pupils
bethanechol chloride (Urecholine)
-Use: increase urination
Indirect-Acting Cholinergic Drugs
-Also called cholinesterase (ChE) inhibitors, and acetylcholinesterase (AChE) inhibitors
-MOA: Inhibits Cholinesterase (ChE) enzyme
-Adverse Effects
↑ GI motility, bradycardia, miosis, bronchial constriction & ↑ urination
-Contraindications
Intestinal and urinary obstruction
Anticholinergics/Parasympatholytics
Other names:
-Cholinergic antagonists
-Muscarinic antagonists
-Antimuscarinic agents
-Antispasmodic agents
Effects of Anticholinergics
-Heart: large doses increase pulse; small doses (less than 0.5 mg) decrease pulse
-Lungs: bronchodilation, decrease secretions
-GI: relax smooth muscle tone, decrease motility & peristalsis, decrease
-GU: relax detrusor muscle, increase sphincter constriction
-Eye: dilate pupils, decrease accommodation
-Mouth: decrease salivation
CNS: decrease tremors & rigidity
Anticholinergics (cont’d)
Uses:
-Dries secretions
-Treat bradycardia
-Parkinson’s disease
-Motion sickness
-Overreactive bladder
-Irritable bowel disease
-Asthma and COPD
