Autonomic Nervous System Sympathetic (Adrenergic) Parasympathetic (Cholinergic) Have a balancing effect Neurotransmitters
Acetycholine (ACH) Norepinephrine (NE) Epinephrine Dopamine Receptors Alpha 1 & 2
Beta 1 & 2 Muscarinic Nicotinie Sympathetic Response
Increase HR Increase RR Increase metabolic rate Increase fat & glycogen breakdown Pupillary dilation Smooth muscle vasoconstriction Skeletal & cardiac muscle vasodilation Decrease GI activity Bronchial relaxation Parasympathetic Response
Decrease HR Decrease RR Increase digestion & elimination Increase GI tone Bronchial constriction Pupillary constriction Cholinergic Agonist (Direct Acting)
Stimulates cholinergic receptors bethanechol chloride (Duvoid, Urecholine) * decreases urinary retention *antidote is atropine pilocarpine (Pilocar) * increases outflow aqueous humor (open angle glaucoma) * pupillary constriction (miosis) & decrease visual acuity
*headache Nicotine Stimulates nicotine receptors Used for cessation of tobacco smoking Cannot smoke when using patch Antichoinesterase
(Indirect-acting Cholinergic Agonists Inhibits enzyme acetlycholinesterase Results in decrease destruction of ACH
Which results in increase cholinergic action Neostigmine (prostigmin) Cholinergic Blockers (anticholergic)
Interrupts parasympathetic nerve impulses Relaxes GI & urinary tract muscles & decrease GI secretions Counteracts bronchospasm & decrease respiratory secretions Decrease salivation Blocks cardiac vagal inhibitions Atropine (cholinergic antagonist)
Blocks actions of ACH at muscarinic receptors blocks vagal effects of SA node (tx bradycardia) preoperative - decrease salivation & respiratory tract secretions bronchodilator
watch for tachycardia, urinary retention, constipation, dry mouth Scopolamine Produces CNS depression with sedative & tranquilizing effects Used to tx motion sickness Anticholinergic Overdose
mad as a hatter (CNS psychotic effect), dry as a bone (salivary), red as a bat (peripheral vasodilation), & blind as a bat (mydriasis) Adrenergic Receptors
Alpha-1 & alpha-2 are differentiated by location on nerve, alpha -1 causes vasoconstriction Beta - 1 primarily located in heart, causes cardiac stimulation Beta - 2 located in smooth muscle of bronchioles, arterioles and visceral organs, relaxation of bronchial & GI Side effects - alpha & beta may have headache, insomnia, restlessness, tachycardia, hypertension, N&V
Summary with receptors Alpha - 1 = vasoconstriction beta - 1 = cardiac stimulation beta - 2 = bronchiole dilation Alpha-1 Adrenergic Agonist
Phenylephrine: most common use is as decongestant, treat nasal congestion Side effects: sleep disturbances, headache Epinephrine (nonselective) (Adrenergic Agonist) Increases heart rate & CO Increase in blood sugar Bronchiole dilation Indicated for anaphylaxis, cardiac arrest, asthma
Beta Adrenergic Agonist Isoproterenal (Isuprel) Increase contractility & heart rate
Bronchodilator Indicated in asthma, bradycardia, cardiac arrest Dopamine (Intropin) Dobutamine (Dobutrex) Proventil & Brethine, respiratory, bronchodilators Alpha Adrenergic Antagonist
Disrupts sympathetic response Relaxation of vascular smooth muscle, peripheral vasodilation & decrease BP prazosin (Minipress) Used for hypertension, angina, peripheral vascular disorders Watch for orthostatic hypotension Beta Adrenergic
Blockers (antagonist) Prevents SNS stimulation decrease peripheral vascular resistance, decrease BP, decrease CO, decrease HR Used to tx hypertension, angina, arrhythmias Beta Blockers
Need to know whether cardioselective or nonselective Beta - 1 blockers will decrease myocardial contractility& HR, Lopressor (metoprolol) & Tenormin (atenolol) Nonselective - blocks beta - 1 and beta -2 which causes above & bronchiole constriction
Propranolol (Inderal) Nonselective Beta Blocker Important to ask if history of asthma, bronchitis, etc. Decrease HR so must check rate
prior to giving client may experience decrease libido or impotence watch for orthostatic hypotension Combined blocker Carvedilol (Coreg) Combined alpha and beta blocker
Frequently administered with other antihypertensive agents. Watch for orthostatic hypotension & bradycardia
