Autonomic Nervous System Agents (ch 18-19) Flashcards
Autonomic Nervous System
“Automatic” or Involuntary
Include Afferent and Efferent neurons
Efferent pathways are divided into Sympathetic and Parasympathetic NS
Peripheral Nervous System
Located outside the CNS
Divided into Automatic and Somatic NS
Sympathetic NS neurotransmitter
Norepinephrine
Parasympathetic NS neurotransmitter
Acetylcholine
Sympathetic Nervous System
“Fight or Flight”
Activated by conditions of stress
Increases HR, BP, CO; dilate brochi, dilates pupils (mydriasis)
Parasympathetic Nervous System
“Rest and Digest”
Promotes digestive processes
Decrease HR, BP; constrict bronchi, contricts pupils (miosis)
Function of Alpha and Beta Adrenergics
“Fight or Flight”
dilates pupils and bronchioles
increses HR
contricts peripheral blood vessels
relaxes bladder.
Alpha1 and Alpha2
Alpha1: bloodvessels (constrict)
Alpha2: bloodvessels (dilate), smooth muscle
Beta1 and Beta2
Beta1: heart
Beta2: lungs
Inactivation of Neurotransmitters
- Reuptake of the transmitter back into the neuron
- Enzymatic transformation or degradation
- Diffusion away from the transmitter
Direct-acting Sympathomimetics
Epinephrine
Directly stimulates
Indirect-acting Sympathomimetics
Amphetamine
Stimulate through and indirect way
Mixed-acting Sympathomimetics
Ephedrine
Epinephrine
Nonselective (Acts on more than one receptor): Alpha1, Beta1, Beta2
Epinephrine: Pharmacodynamics
- Treats anaphylaxis
- Increases CO, HR, and systolic BP
- Promotes vasoconstriction
- Bronchodilation
- Renal vasoconstriction (decresing UO)
- Onset of action and peak concentration are rapid
Epinephrine: Pharmacokinetics
- ROA: Subcut, IV, topically, inhalation, intracardiac, instillation
- Is rapidly metabolized by the GI tract and liver so it should not be given PO
- Half-life and protein binding is unknown
Epinephrine: Contraindications and Cautions
- Cardiac disrythmias
- Glaucoma (aqueous humor), BPH
- Hypertension
- Hyperthyroidism
- Pregnancy
Norepinephrine
- Alpha1, Beta1
- Used for shock, potent vasoconstrictor
- Given IV as infusion, titrated (seen in ICU)
Dopamine
- Alpha1, Beta1, Dopaminergic
- Used to treat hypotension/shock
- Increases renal perfusion (low dose)
- Increases BP (higher dose)
- IV infusion
Albuterol
- Selective: Beta2
- Used to treat bronchospasm, asthma, bronchitis, COPD
- Oral, inhaler, nebulizer
Doputamine
- Selective: Beta1
- Used to treat cardiac decompensation by enhancing myocardial contractility, SV, CO; used to treat CHF
- IV with dose titrated to achieve effect
Terbutaline Sulfate
- Selective: Beta2
- Used to treat bronchospasm or premature labor
- PO, SC, or IV
Pseudoephedrine
- Alpha1, Beta1
Alpha1 Receptor Blocker Effects
- Vasodilation, decrease in BP, miosis, reduction in contraction of smooth muscles in bladder neck and prostate gland
- Used for hypertension and BPH
- Side Effects: Cardiac disrythmias, flushing, hypotension, reflex tachycardia
List the Alpha1 Receptor Blockers
-osin
Prazosin: (Minipress) hypertension, angina, CHF, BPH, vasospasms associated with Raynaud’s
Doxazosin: (Cardura) hypertension, BPH
Tamsulosin: (Flomax) BPH
Terazosin: (Hytrin) BPH
*Phentolomine: (Regitine) used to block the effects of infiltrated alpha agonists like dopamine or dobutamine
Nonselective Beta-Adrenergic Blockers
-olols
Used to treat hypertension, angina, dysrythmias
Propranolol: (Inderal)
Contraindications: Allergy, bradycardia, heart block, shock, CHF, bronchspasm, COPD, asthma, pregnancy, lactation, diabetic/hypoglycemic, thyrotoxicosis, hepatic dysfunction…
Side Effects/Adverse Reactions: bradycardia, laryngospasm, dysrythmias, hypotension, headaches, hyperglycemia/ hypoglycemia, agranulocytosis, impotence, decreased labido…
Drug Interactions: almost everything!
-olol
Beta-Adrenergic Blockers
-osin
Alpha1 receptor blockers
Alpha-beta Adrenergic Blockers
Carvedilol (Coreg)
Labetalol
Selective Beta Blockers
Used to treat hypertension and glaucoma
Metoprolol tartrate (Lopressor)*
Atenolol (Tenormin)
Betaxolol (Kerlone, Betoptic)
Nebivolol (Bystolic)
Contraindications, side effects, & adverse effects same as propranolol
*one of the top 15 drugs in 2009
First Dose Hypotension
Given at night because of relaxed vascular system, they stand up and the blood falls to their feet.
Are you able to suddenly discontinue any beta blocker?
No! Dose should be tapered off.
Client Teaching for Beta-Blocker patients
- Get out of bed slowly
- Monitor Pulse (60-100)
- Do not discontinue abruptly (up to 2 wks)
- Take at the same time each day even if they feel “OK”
Cholinergics/Parasympathomimetics
Neurotransmitter
Acetylcholine (Ach)
Cholinergics/Parasympathomimetics
Receptors
Muscarinic receptors
Nicotine Receptors
Cholinergics/Parasympathomimetics
Effects on body organs
Cholinergic nerve is Vagus Nerve
Increases Peristalisis
Contracts Bladder
Direct-Acting Cholinergic Drugs
Metoclopramide HCl (Reglan): PO/IM/IV; GI stimulant, antiemetic
Pilocarpine HCl (Pilocar): opthalmic drops; reduce intraocular pressure
Bethanechol chloride (Urecholine): treats urinary retention, abdominal distension
*All are muscarinic*
Indirect-Acting Cholinergic Drugs
Reversible
Myasthenia Gravis: must take meds on time
- Ambenonium (Mytelase)
- Endrophonium (Tensilon, Enlon)
- Neostigmine (Prostigmine)
- Pyridostigmine (Regonol, Mestinon)
Alzheimer’s Disease: prolong patient’s functionality
- Donepezil (Aricept)
- Galantamine (Razadyne)
- Rivastigmine (Excelon)
- Tacrine (Cognex)
Indirect-Acting Cholinergic Drugs
Irreversible
Used therapeutically to produce pupillary constriction
Used in the manufacture of insecticides
Used as a WOMD
Anticholinergics/Parasympatholytics
AKA: cholinergic blocking agents, cholinergic or muscarinic antagonists, antimuscularinic agents, antispasmodic agents
Used for management of bradycardia, to dry up secretion, and calm GI tract, to paralyze Parkinson’s Disease
Anticholinergics/Parasympatholytics
Atropine
- Decreases secretions in preop patients
- Acts as antispasmodic to treat peptic ulcers (drys up secretions)
- Increaes HR in bradycardia
- Antidote for muscarinic agonist poisoning
- Side & Adverse Effects: tachycardia, dry mouth, abdominal distension, palpations, nasal congestion, photophobia, blurred vision, flushing, urinary distention
Anticholinergics/Parasympatholytics
Scopolamine
(Transderm Scop)
motion sickness
decrease secretions
obstetric amnesia
relief of urnary problems
IBS
Anticholinergics/Parasympatholytics
Dicyclomine
(Antispas, Bentyl)
hyeperactive bowel
Anticholinergics/Parasympatholytics
Hyoscyamine SO4
(Levsin)
peptic ulcers
IBS
Anticholinergics/Parasympatholytics
Glycopyrrolate
(Robinul)
decrease secretions
antidote for neuromuscular blockers
Anticholinergics/Parasympatholytics
Propantheline
(Pro-Banthers)
ulcers
antisecretory
antispasmodic
Anticholinergics/Parasympatholytics
Cyclopentolate HCl
(Cyclogyl)
for mydriasis and cycloplegia for eye exams (dilation)
Anticholnergics used for Tx of Parkinson’s Dz
Bentropine mesylate (Cogentin)
Biperiden lactate (Akineton)
Trihexphyenidyl HCl (Artane)
Acetylcholinesterase
Breaks down Ach, increasing the amt of Ach in the body.
Adverse Effects of Anticholinergics
Red as a beet
Dry as a bone
Mad as a hatter
Hot as a hare
Can’t see…Can’t pee
Can’t spit…Can’t shit!
