suekeeadrenergicdrugs

suekeeadrenergicdrugs - Adrenergics and Adrenergic...

Info iconThis preview shows pages 1–36. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Adrenergics and Adrenergic Adrenergics and Adrenergic Blockers Susan Hampson Spring 2010 The Nervous System The Nervous System CNS ◦ Central nervous system; includes brain and spinal cord PNS ◦ Peripheral nervous system; includes somatic, autonomic divisions ◦ Autonomic division further divided Sympathetic Parasympathetic Autonomic Nervous System Autonomic Nervous System Three Principle Functions ◦ Regulation of heart ◦ Regulation of secretory glands ◦ Regulation of smooth muscles Autonomic Nervous System Autonomic Nervous System Afferent nerves­ carry impulses from all parts of the body TO the brain Efferent nerves­ carry impulses AWAY from brain to body Unconscious regulation is result! Patterns of Patterns of Innervation/Control Three patterns of autonomic innervation and regulation ◦ Opposing ◦ Complimentary ◦ Solo Autonomic Pharmacology Autonomic Pharmacology Resting activity maintained by opposing influences from ◦ Sympathetic (Adrenergic) ◦ Parasympathetic (Cholinergic) divisions Autonomic Nervous System Autonomic Nervous System Sympathetic Division ◦ “Fight or flight” ◦ Activated under stress or emergency conditions ◦ Adrenergic drugs can cause stimulation (agonist) or inhibition (antagonist) of this division ◦ Can affect many sites (nonselective) or just one or a few sites (selective) Adrenergics Adrenergics Function of adrenergics Sympathetic responses. Adrenergics (cont’d) Adrenergics (cont’d) Effects of adrenergic receptor sites ◦ Alpha1 Increase cardiac contractility, vasoconstriction Dilate pupils, decrease salivary gland Dilate pupils, decrease salivary gland secretion Increase bladder and prostate contraction Increase bladder and prostate contraction ◦ Alpha2 Inhibit norepinephrine release Promotes vasodilation Promotes vasodilation Adrenergics (cont’d) Adrenergics (cont’d) Effects of adrenergic receptor sites ◦ Beta1 B Increase cardiac contractility, P Increase renin secretion, BP Increase renin secretion, BP ◦ Beta2 B Decreases GI tone and motility Bronchodilation Bronchodilation Increases blood flow in skeletal muscles Increases blood flow in skeletal muscles Decreases uterine tone Decreases uterine tone Activates liver glycogenolysis Activates liver glycogenolysis Increases blood glucose Increases blood glucose Adrenergics (cont’d) Adrenergics (cont’d) Effects of adrenergic receptor sites ◦ Dopaminergic Vasodilation Vasodilation Increases blood flow Increases blood flow Neurotransmitter Neurotransmitter Inactivation Inactivation ◦ Reuptake of transmitter ◦ Enzymatic transformation or degradation MAO inside neuron MAO inside neuron COMT outside neuron COMT outside neuron ◦ Diffusion away from the transmitter Drugs halt termination of neurotransmitter ◦ By inhibiting norepinephrine reuptake ◦ By inhibiting norepinephrine degradation Classification of Classification of Adrenergics/Sympathomimetics Direct-acting Indirect-acting Epinephrine Amphetamine Mixed-acting Ephedrine Catecholamines Catecholamines Catecholamines Endogenous • Epinephrine, norepinephrine, dopamine Synthetic • Isoproterenol, dobutamine Noncatecholamines Most have longer duration of action then Most endogenous and synthetic endogenous • Phenylephrine, metaproterenol, albuterol Epinephrine (Adrenalin) Epinephrine (Adrenalin) Nonselective Action ◦ Alpha1 increases the blood pressure ◦ Beta1 increases heart rate ◦ Beta2 promotes bronchodilation ◦ Contraindications and caution Cardiac dysrhythmias, hypertension ◦ Hyperthyroidism ◦ Pregnancy Epinephrine (Adrenalin) (cont’d) Epinephrine (Adrenalin) (cont’d) Actions ◦ Inotropic ◦ Vasoconstrictor ◦ Bronchodilator Uses ◦ Anaphylaxis, anaphylactic shock ◦ Bronchospasms ◦ Cardiogenic shock, cardiac arrest Epinephrine (Adrenalin) (cont’d) Epinephrine (Adrenalin) (cont’d) Side effects/adverse reactions ◦ Cardiac dysrhythmias ◦ Hypotension, flushing, reflex tachycardia ◦ Decrease renal perfusion Drug interaction ◦ Beta-blockers (βBs) B Decreases epinephrine action ◦ Digoxin Causes cardiac dysrhythmias Causes cardiac dysrhythmias Epinephrine (Adrenalin) (cont’d) Epinephrine (Adrenalin) (cont’d) Nursing Interventions ◦ Monitor BP, P, urine output ◦ Report tachycardia, palpitations, tremors, dizziness, hypertension ◦ Monitor IV site for infiltration Antidote: phentolamine mesylate (Regitine) Antidote: phentolamine mesylate (Regitine) ◦ Avoid cold medications/diet pills if hypertensive, diabetic, CAD, or dysrhythmias ◦ Avoid adrenergics when nursing infants ◦ Avoid continuous use of adrenergic nasal sprays Alpha 1 Adrenergic Agonist: Alpha 1 Adrenergic Agonist: Phenylephrine (Allerest) Most often used for relief of nasal congestion, dilation of pupil Common routes topical, IV Poorly absorbed orally Systemic effect is VASOCONSTRICTION ◦ Increase BP, PVR ◦ Decrease renal perfusion, CO Alpha 2 Agonist: Alpha 2 Agonist: Clonidine(Catapres) Used to treat hypertension Inhibits release of norepinephrine Stimulates receptors in CNS Beta 1 Adrenergic Agonist: Beta 1 Adrenergic Agonist: Dopamine Treats hypotension in shock NOT caused by hypovolemia Parenteral route only as continuous infusion Causes increase in force and rate of cardiac contraction Low vs. high dosing Albuterol (Proventil) Albuterol (Proventil) Selective ◦ Acts on β2 adrenergic receptors ◦ Promotes bronchodilation Uses ◦ Treat bronchospasm, asthma, bronchitis, COPD Caution ◦ Severe cardiac disease ◦ Hypertension, hyperthyroidism ◦ Diabetes mellitus, pregnancy Albuterol (Proventil) (cont’d) Albuterol (Proventil) (cont’d) Side effects/adverse reactions ◦ Tremors, nervousness, restlessness ◦ Dizziness, reflex tachycardia ◦ Hallucinations ◦ Cardiac dysrhythmias Drug interaction ◦ May increase effect with other sympathomimetics, MAO inhibitors & tricyclic antidepressants ◦ Antagonize effect with βBs Adrenergic Blockers Adrenergic Blockers (Antagonists) Block effects of adrenergic neurotransmitter ◦ Block alpha and beta receptor sites Directly: by occupying receptors Directly: by occupying receptors Indirectly: by inhibiting release of Indirectly: by inhibiting release of neurotransmitters epinephrine and norepinephrine Effects of Adrenergic Blockers Effects of Adrenergic Blockers at Receptors Alpha1 ◦ Vasodilation, decrease BP, reflex tachycardia ◦ Pupil constriction ◦ Suppresses ejaculation ◦ Reduces contraction of smooth muscles in bladder neck and prostate Effects of Adrenergic Blockers Effects of Adrenergic Blockers at Receptors (cont’d) Beta1 ◦ Reduces cardiac contractility ◦ Decreases pulse Beta2 ◦ Bronchoconstriction ◦ Contracts uterus ◦ Inhibits glycogenolysis Alpha Blockers Alpha Blockers Drugs that inhibit a response at alpha­adrenergic receptor site ◦ Selective Block alpha1 Block alpha1 ◦ Nonselective Block alpha1 and alpha2 Block alpha1 and alpha2 ◦ Action Promotes vasodilation Promotes vasodilation ◦ Use Decrease symptoms of BPH, PVD Beta­Adrenergic Blockers Beta­Adrenergic Blockers Beta­blockers (βBs) action ◦ Decrease BP and Pulse Nonselective beta blockers ◦ Blocks beta1 Decrease BP and P Decrease BP and P ◦ Blocks beta2 Bronchostriction Bronchostriction ◦ Propranolol HCl (Inderal) Uses Uses Angina, cardiac dysrhythmias, hypertension, heart failure Beta­Adrenergic Blockers (cont’d) Beta­Adrenergic Blockers (cont’d) Nonselective (Propranolol) Inderal ◦ Contraindications COPD COPD ◦ Side effects/adverse reactions Weight gain, impotence, decreased libido, Weight gain, impotence, decreased libido, reversible alopecia ◦ Drug interactions Decreased drug effects with phenytoin, Decreased drug effects with phenytoin, isoproterenol, NSAIDs, barbiturates, caffeine, theophylline Heart block may occur with digoxin, calcium Heart block may occur with digoxin, calcium channel blockers Beta­Adrenergic Blockers (cont’d) Beta­Adrenergic Blockers (cont’d) Selective beta blockers ◦ Blocks beta1 only Decrease BP and P Decrease BP and P Fewer side effects Fewer side effects ◦ Metoprolol (Lopressor), atenolol (Tenormin) ◦ Side effects/adverse reactions Bradycardia, hypotension, dysrhythmias, Bradycardia, hypotension, dysrhythmias, headaches, dizziness, fainting, fatigue, mental depression, nausea, vomiting, diarrhea, blood dyscrasias, hypoglycemia Beta­Adrenergic Blockers (cont’d) Beta­Adrenergic Blockers (cont’d) Drug interactions ◦ Decreased effects with NSAIDs ◦ Increased effects with prazosin, terazosin, atropine, anticholinergics ◦ Increased risk of hypoglycemia Insulin, sulfonylureas Insulin, sulfonylureas Case Study Case Study A client visiting the outpatient health clinic complains of dizziness when standing, fatigue, severe headache, and depression. Assessment reveals a heart rate of 55 and blood pressure of 110/70. He has a history of hypertension and is taking an antihypertensive. Critical Thinking What drugs might cause some of these symptoms as side effects? Compare the action and side effects of alpha­ and beta­ adrenergic blockers. Practice Question #1 Practice Question #1 Which is the nurse’s highest priority when teaching about side effects/adverse reactions to a client who is taking metoprolol (Lopressor)? A. Report any complaints of stuffy nose. B. Instruct the client how to take a pulse. C. Check urine output and bladder distention. D. Warn of possible impotence and decreased libido. Practice Question #2 Practice Question #2 Which drug may interact with propranolol (Inderal)? A. An antacid B. Phenytoin C. Phentolamine D. A tricyclic antidepressant ...
View Full Document

Page1 / 36

suekeeadrenergicdrugs - Adrenergics and Adrenergic...

This preview shows document pages 1 - 36. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online