ANS Drugs PDF - La Consolacion University Philippines

LA CONSOLACION UNIVERSITY PHILIPPINES College of Allied Medical Professions Bachelor of Science in Nursing NCM 106: NURSING PHARMACOLOGY  OPENING PRAYER Lord God of all wisdom, We pray for the La Consolacion Universi...

LA CONSOLACION UNIVERSITY PHILIPPINES College of Allied Medical Professions Bachelor of Science in Nursing NCM 106: NURSING PHARMACOLOGY  OPENING PRAYER Lord God of all wisdom, We pray for the La Consolacion University Philippines that she may be faithful to the purposes of our foundresses, continue to promote the search for truth and knowledge, and be an inspiration for others to follow. May we be a community of scholars sharing this ambition, caring for one another, and being loyal to the truth revealed to us as your disciples. AMEN. DRUGS AFFECTING THE AUTONOMIC NERVOUS SYSTEM  ANS DRUGS Adrenergic agonists and antagonists Cholinergic agonists and antagonists  LEARNING OBJECTIVES: By the end of this lecture, students will be able to: 1. Understand the major responses to stimulation of adrenergic and cholinergic receptors. 2. Differentiate between adrenergic and cholinergic agonists and antagonists. 3. Contrast the uses of alpha and beta antagonists. 4. Describe nursing interventions, including patient teaching, associated with adrenergic agonists and adrenergic antagonists. ANS DRUGS  ANS DRUGS Somatic NS: activates skeletal muscles; VOLUNTARY Autonomic NS: influences organs, glands, smooth muscles; INVOLUNTARY  ANS DRUGS The autonomic nervous system (ANS) plays a pivotal role in regulating involuntary bodily functions, including heart rate, digestion, respiratory rate, and pupillary response. ANS DRUGS  ANS DRUGS The autonomic nervous system consists of two main divisions: Sympathetic nervous system Parasympathetic nervous system These divisions often work antagonistically to regulate physiological functions.  ANS DRUGS The sympathetic nervous system (ANS) prepares the body for “fight or flight” responses. It readies the body for an immediate response to a potential threat.  ANS DRUGS The sympathetic nervous system (ANS) arises from the thoracolumbar region of the spinal cord. Preganglionic neurons is made up of “fibers” that exit through the thoracolumbar spinal nerves.  ANS DRUGS Preganglionic: Cholinergic fibers = Acetylcholine (AChE) Memory, learning, attention, arousal and involuntary muscle movement Stimulates postganglionic neurons which contains “adrenergic fibers” Epinephrine, NE, DA  ANS DRUGS Postganglionic: Adrenergic fibers = Norepinephrine (NE) Neurotransmitter which acts on alpha and beta receptors HR, bronchodilation, mydriasis, etc. ANS DRUGS ANS DRUGS  ANS DRUGS The parasympathetic nervous system (ANS) conserves energy and promotes “rest and digest” activities. Digestive processes promoted; HR and BP declined.  ANS DRUGS The parasympathetic nervous system (ANS) originates from the craniosacral region CN III, VII, IX, X Sacral nerves ANS DRUGS ANS DRUGS  ANS DRUGS Four main receptors: Alpha 1 receptors Alpha 2 receptors Beta 1 receptors Beta 2 receptors  ANS DRUGS Alpha 1 receptors: located in the blood vessels, eyes, bladder, and prostate Alpha 2 receptors: located in the postganglionic sympathetic nerve endings that INHIBIT NE release– blood vessels and smooth muscles ANS DRUGS  ANS DRUGS Beta 1 receptors: located primarily in the heart but also in the kidneys. Stimulation increases myocardial contraction and heart rate. Beta 2 receptors: located mostly in the smooth muscles of the lung, GI tract, liver, and uterine muscle. ANS DRUGS  ANS DRUGS Adrenergic Agonists Drugs Adrenergic agonists, adrenergic, sympathomimetics They mimic the sympathetic neurotransmitters NE and Epi. Classification of Sympathomimetics: A. Direct-acting sympathomimetics B. Indirect-acting sympathomimetics C. Mixed-acting (both direct- and indirect-acting) sympathomimetics  ANS DRUGS Adrenergic Agonists Drugs A. Direct-acting sympathomimetics - Directly stimulate the adrenergic receptors Ex: Epinephrine, Norepinephrine B. Indirect-acting sympathomimetics - Stimulates the release of NE from the terminal nerve endings Ex: Amphetamine (ADHD, narcolepsy) C. Mixed-acting sympathomimetics - Stimulates the adrenergic receptor sites and release of NE from the terminal nerve endings Ex: Ephedrine (perioperative hypotension)  ANS DRUGS Alpha 1 agonists: Epinephrine, Ephedrine, Dopamine, Phenylephrine, Midodrine Alpha 2 agonists: Clonidine, Methyldopa Beta 1 agonists: Epinephrine, Ephedrine, Dopamine, Dobutamine, Isoproterenol Beta 2 agonists: Epinephrine, Ephedrine, Isoproterenol, Albuterol, Terbutaline, Metaproterenol Mixed (Alpha and Beta-agonists): Epinephrine, NE, Ephedrine, Dopamine, Pseudoephedrine  ANS DRUGS Alpha 1 agonist Indication: Nasal congestion, hypotension, or pupillary dilation Administration: PO, sprays Max: 60 mg/day PO, 3 sprays per nostril in 4 hours period for 3 days  ANS DRUGS Alpha 1 agonist Mechanism of action: Activation of α1-adrenoceptors in the arterioles of the nasal mucosa with little effect on the beta receptors of the heart, lacking chronotropic and inotropic actions on the heart.  ANS DRUGS Alpha 1 agonist Nursing considerations: Known hypersensitivity to phenylephrine Severe hypertension, ventricular tachycardia Caution in neonates with hyperthyroidism, hypertension, myocardial disease, heart block, bradycardia, bronchopulmonary dysplasia, and narrow-angle glaucoma Blood pressure and heart rate should be monitored.  ANS DRUGS Alpha 1 agonist Indication: Orthostatic hypotension Administration: PO Max: 30 mg/day PO Warning: Do NOT administer within 4 hours of bedtime = supine hypertension  ANS DRUGS Alpha 1 agonist Mechanism of action: An α1-adrenergic receptor agonist exerts its actions via activation of α1-adrenergic receptors of the arteriolar and venous vasculature, producing an increase in vascular tone and elevation of blood pressure.  ANS DRUGS Alpha 1 agonist Nursing considerations: May cause hypertension, paresthesias, pruritus, abdominal pain, urinary retention/urgency, dysuria Blood pressure checks and a kidney function blood test should be carried out before starting midodrine. Blood pressure and heart rate should be monitored during treatment with midodrine. It is especially important to have your blood pressure checked after lying down.  ANS DRUGS Alpha 2 agonist Indication: Hypertension, Pulmonary hypertension Administration: PO SL, transdermal Initially: 0.1 mg bid Maintenance: 0.2-0.6 mg/day Max: 2.4 mg/day Transdermal: 1 patch q7d  ANS DRUGS Alpha 2 agonist Mechanism of action: Stimulates alpha-2 adrenoreceptors in the brain stem. This results in reduced sympathetic outflow from the central nervous system and decreases in peripheral resistance, renal vascular resistance, heart rate and blood pressure  ANS DRUGS Alpha 2 agonist Nursing considerations: Monitor blood pressure and pulse rate frequently. Dosage is usually adjusted to the patient’s blood pressure and can cause hypotension, bradycardia, and sedation. Rebound hypertension may occur if stopped abruptly. May cause dizziness, drowsiness, confusion, fatigue, pruritus, nausea, vomiting, abdominal pain, constipation, dry mouth, orthostatic hypotension, bradycardia, anxiety, edema  ANS DRUGS Alpha 2 agonist Indication: Pre-eclampsia, gestational hypertension Administration: PO Initially: 250 mg bid-tid Maintenance: 500-2000 mg/day in 2-4 divided doses Max: 3 g/day  ANS DRUGS Alpha 2 agonist Mechanism of action: Works by binding to alpha(α)-2 adrenergic receptors as an agonist, inhibiting adrenergic neuronal outflow and reducing vasoconstrictor adrenergic signals.  ANS DRUGS Alpha 2 agonist Nursing considerations: For I.V. infusion, add methyldopate to 100 ml of D5W and administer over 30 to 60 minutes. Monitor blood pressure regularly during therapy. Monitor results of Coombs’ test; a positive result after several months of treatment indicates that patient has hemolytic anemia. Expect to discontinue drug. Assess for edema and weight gain. If they develop, give a diuretic. Be aware that hypertension may return within 48 hours after stopping drug.  ANS DRUGS Beta 1 agonist Indication: Cardiogenic shock ( CO), heart failure, and cardiac surgery Administration: IV Initially: 0.5-1 mcg/kg/min Max: 20 mcg/kg/min  ANS DRUGS Beta 1 agonist Mechanism of action: Stimulates beta-1 adrenergic receptors which produces a positive inotropic effect on the myocardium, increasing cardiac output by boosting myocardial contractility and stroke volume.  ANS DRUGS Beta 1 agonist Nursing considerations: Avoid giving dobutamine to patients with uncorrected hypovolemia. Expect prescriber to order whole blood or plasma volume expanders to correct hypovolemia Also avoid giving dobutamine to patients with acute MI because it can intensify or extend myocardial ischemia. Use drug cautiously in patients allergic to sulfites because drug may cause anaphylactic-like signs and symptoms  ANS DRUGS Beta 1 agonist Nursing considerations: Dilute concentrate with at least 50 ml compatible I.V. solution. A common dilution is 500 mg (40 ml from 250-ml bag) in 210 ml D5W or NSS to yield 2,000 mcg/ml. Or dilute 1,000 mg (80 ml from 250-ml bag) in 170 ml D5W or NSS to yield 4,000 mcg/ml. Give I.V. drug using an infusion pump. Monitor blood pressure continuously during therapy, preferably by continuous intra-arterial monitoring. Monitor heart rate and rhythm via ECG recordings continuously  ANS DRUGS Beta 2 agonist Indication: Prophylaxis and treatment of bronchospasm (exercise-induced), acute asthma attacks Administration: PO, inhalation Initially (for IR): 2-4 mg q6-q8h Max: 32 mg/day Initially (for XR): 4-8 mg q12h Max: 32 mg/day Inhalation: Two inhalations 15 to 30 min before exercise  ANS DRUGS Beta 2 agonist Mechanism of action: Attaches to beta 2 receptors on bronchial cell membranes. It promotes the production of intracellular cyclic adenosine monophosphate (cAMP), which enhances the binding of intracellular calcium to the cell membrane. This action decreases the calcium concentration within cells and results in the relaxation of smooth muscle and bronchodilation.  ANS DRUGS Beta 2 agonist Nursing considerations: Administer pressurized inhalations of albuterol during second half of inspiration, when airways are open wider and aerosol distribution is more effective Monitor serum potassium level because albuterol may cause transient hypokalemia Use cautiously in patients with cardiac disorders, diabetes mellitus, digitalis intoxication, hypertension, hyperthyroidism, or history of seizures. Albuterol can worsen these conditions. ANS DRUGS  ANS DRUGS Adrenergic Antagonists Drugs Adrenergic antagonists, adrenergic blockers, sympatholytics They block the alpha- or beta-receptor sites by inhibiting the release of NE and epinephrine. a) Alpha 1 blocker: decreases BP, miosis, reduces contraction of the bladder and prostate. b) Beta 1 blocker: decreases HR; reduces the force of contractions c) Beta 2 blocker: constricts bronchioles and uterus, and inhibits glycogenolysis which decreases blood glucose.  ANS DRUGS Alpha 1 antagonists: Phentolamine, Prazosin, Terazosin, Tamsulosin Alpha 2 antagonists: Prazosin, Yohimbine, Mirtazapine Beta 1 antagonists: Carvedilol, Labetalol, Atenolol, Metoprolol, Acebutolol, Betaxolol, Bisoprolol, Esmolol, Nebivolol, Propranolol, Nadolol, Pindolol, Sotalol, Timolol Beta 2 antagonists: Carvedilol, Labetalol, Propranolol, Nadolol, Pindolol, Sotalol, Timolol Mixed (Alpha and Beta-antagonists): Carvedilol, Labetalol  ANS DRUGS Alpha 1 antagonists: Prazosin, Terazosin, Doxazosin, Tamsulosin, Indication: Benign prostatic hyperplasia, Hypertension Administration: PO Terazosin, Doxazosin: longer half-lives than prazosin; given with diuretics Tamsulosin: most selective for prostatic smooth muscle  ANS DRUGS Alpha 1 antagonist Mechanism of action: Inhibits alpha1-adrenergic receptors by promoting peripheral arterial and venous dilation and reduces peripheral vascular resistance, thereby lowering blood pressure. Relaxes smooth muscle of the bladder neck, prostate, and prostate capsule, which reduces urethral resistance and pressure and urinary outflow resistance.  ANS DRUGS Alpha 1 antagonist Nursing considerations: Be aware that prostate cancer should be ruled out before giving treatment for BPH begins. Expect prescriber to reduce dosage if a diuretic or another antihypertensive is added to patient’s regimen. Monitor blood pressure 2 to 3 hours after initial dose because of possible first-dose hypotension and again after 24 hours to evaluate patient’s response If patient requires administration by feeding tube, place capsule in 60 ml of warm tap water. Stir until capsule shell dissolves and liquid contents are released into water (5 to 10 minutes).  ANS DRUGS Alpha 2 antagonist: Yohimbine (Obsolete) Indication: Benign prostatic hyperplasia, Hypertension Has been associated with heart attacks and seizures due to inaccurate labeling and potential serious side effects.  ANS DRUGS Beta adrenergic antagonists: -olols -AKA beta blockers which decrease heart rate, and a decrease in blood pressure usually follows. Bronchoconstriction also occurs. Nonselective beta blockers block both beta1 and beta2 and should be used with extreme caution in any patient who has chronic obstructive pulmonary disease (COPD) or asthma. Ex: Carvedilol, Labetalol, Propranolol, Nadolol, Pindolol, Sotalol, Timolol  ANS DRUGS cAMP activates protein kinase A (PKA) which phosphorylates multiple proteins in smooth muscle cells leading to relaxation, or in airway epithelial cells to increased ciliary beating.  ANS DRUGS Beta adrenergic antagonists: -olols Selective adrenergic antagonists have greater affinity for certain receptors. If the desired effect is to decrease pulse rate and blood pressure, a selective beta1 blocker is given. Ex: Atenolol, Metoprolol tartrate  ANS DRUGS better suited for patients with asthma or restrictive airway disease.  ANS DRUGS Beta adrenergic antagonist Mechanism of action: - Reduces cardiac output and tachycardia, causes vasodilation, and decreases peripheral vascular resistance, which reduces blood pressure and cardiac workload. - It blocks the release of the stress hormones adrenaline and noradrenaline in certain parts of the body. - It decreases myocardial oxygen demand, which helps prevent anginal pain and death of myocardial tissue.  ANS DRUGS Beta adrenergic antagonist Nursing considerations: Use cautiously in patients with bronchospastic lung disease because it may induce asthmatic attack, and in patients with underlying skeletal muscle disease; isolated reports of myopathy and myotonia have occurred. Hypersensitivity to beta blockers. Use cautiously in diabetic patients because it may mask tachycardia caused by hypoglycemia. Monitor patient for heart failure. Stop the medication and notify prescriber if patient develops bradycardia, hypotension, or other serious adverse reaction.  ANS DRUGS Parasympathetic Nervous System -Cholinergic System-  ANS DRUGS The neurotransmitter at the end of the neuron that innervates the muscle is: _c_ _ y _ _ _ o _ i _ _?  ANS DRUGS The neurotransmitter at the end of the neuron that innervates the muscle is: Acetylcholine  ANS DRUGS Cholinergic Agonists - Direct-Acting Cholinergic Agonists - Indirect-Acting Cholinergic Agonists Cholinergic Antagonists - Atropine - Antiparkinson Anticholinergic Drugs - Anticholinergics for Treating Motion Sickness ANS DRUGS  ANS DRUGS Nicotinic receptors Muscarinic receptors - stimulated by nicotine alkaloid - stimulated by muscarine - function within the CNS and at the alkaloid neuromuscular junction (connection - function in both the PNS and between the terminal end of a CNS, mediating innervation to motor nerve and a muscle) visceral organs (sweat, - mediate fast excitatory lacrimal, salivary, mammary, neurotransmission at the and digestive glands) neuromuscular junction and at - respond more slowly than autonomic ganglia nicotinic receptors ANS DRUGS  ANS DRUGS Cholinergic Agonists - Also known as parasympathomimetics - Drugs that stimulate the parasympathetic nervous system - 2 types of cholinergic agonists: a. Direct-acting cholinergic agonists- which act on receptors to activate a tissue response b. Indirect-acting cholinergic agonists- which inhibit the action of the enzyme cholinesterase (ChE), also called acetylcholinesterase (AChE) ANS DRUGS  ANS DRUGS Direct-acting cholinergic agonists Acetylcholine Directing-acting muscarinic ○ Bethanechol (postoperative urinary retention, postpartum urinary retention), Carbachol (IOP) ○ Pilocarpine, Cevimeline (Sjogren's syndrome) Direct-acting nicotinic ○ Nicotine, Varenicline, Lobeline ○ Succinylcholine, Suxamethonium chloride  ANS DRUGS Indirect-acting cholinergic agonists Edrophonium (Myasthenia gravis) Carbamates (-stigmines) Organophosphates (Parathion, Malathion, Tabun, Sarin, Soman) Drugs for Alzheimer’s disease ○ Rivastigmine ○ Donepezil ○ Galantamine ○ Tacrine  ANS DRUGS Effects of Cholinergic agonists: Cardiovascular __ HR, __ BP Gastrointestinal __ tone and motility of smooth muscle of stomach and intestine, __ peristalsis, and relaxed sphincter muscles Genitourinary Contraction of muscles of the urinary bladder, increased tone of ureters, relaxed bladder sphincter muscles, and stimulated urination Ocular Increased pupil constriction or miosis and increased accommodation (flattening or thickening of eye lens for distant or near vision)  ANS DRUGS Effects of Cholinergic agonists: Glandular __ salivation, perspiration, and tears Bronchial Stimulation of bronchial smooth muscle contraction and increased bronchial secretions Striated muscle Increased neuromuscular transmission and maintenance of muscle strength and tone  ANS DRUGS Cholinergic Antagonists - Also known as parasympatholytics or anticholinergics - Drugs that inhibit the actions of acetylcholine by occupying the acetylcholine receptors - Major responses to anticholinergics: decrease in GI motility decrease in salivation mydriasis increase in pulse rate  ANS DRUGS Anticholinergic Response: The anticholinergic drug occupies the receptor sites, blocking acetylcholine. ACh, Acetylcholine; D, anticholinergic drug.  ANS DRUGS Other effects of anticholinergics: - decreased bladder contraction urinary retention - decreased rigidity and tremors related to neuromuscular excitement - act as an antidote to the toxicity caused by cholinesterase inhibitors and organophosphate ingestion  ANS DRUGS Effects of Cholinergic antagonists: Cardiovascular increase HR with large doses, small doses can decrease HR Gastrointestinal Relaxed smooth muscle tone of GI tract, decreased GI motility and peristalsis; gastric and intestinal secretions are decreased Genitourinary Relaxed bladder detrusor muscle and increased constriction of internal sphincter = urinary retention Ocular Dilated pupils (mydriasis) and paralyzed ciliary muscles (cycloplegia)  ANS DRUGS Effects of Cholinergic antagonists: Glandular Salivation, perspiration, and bronchial secretions are decreased Bronchial Bronchodilation Striated muscle Tremors and rigidity of muscles are decreased; drowsiness, disorientation, and hallucinations can result from large doses.  ANS DRUGS Muscarinic antagonists: Atropine, Homatropine, Cyclopentolate, Tropicamide blocks ALL muscarinic receptors Ipratropium bromide, Tiotropium Scopolamine/Hyoscine Dicyclomine Oxybutynin, Darifenacin, Fesoterodine (Overactive bladder) Pirenzepine, Telenzepine (PUD)  ANS DRUGS Nicotinic antagonists: Hexamethonium, Trimethaphan, Mecamylamine Obsolete use in hypertension Tubocurarine, Pancuronium, Atracurium, Vecuronium Skeletal muscle relaxation prior to surgery ANS DRUGS  Q & A PORTION: Any Questions?  THANK YOU ID PICTURE Thank you Danlled P. Javier, RPh, PharmD for listening! [email protected]  BIBLIOGRAPHY Cholinergic medications. (2024, January 1). PubMed. https://pubmed.ncbi.nlm.nih.gov/30844190/ Comerford, K.C. & Durkin, M.T. (2024). Nursing 2024 drug handbook. (44th edition.) Philadelphia: Wolters Kluwer. Farzam, K., Kidron, A., & Lakhkar, A. D. (2023, July 2). Adrenergic drugs. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK534230/ Mccuistion (2023). Pharmacology: a Patient-Centered Nursing Process approach. Nursing, O. R. F., Ernstmeyer, K., & Christman, E. (2023). Chapter 4 Autonomic nervous system. Nursing Pharmacology - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK595003/  CLOSING PRAYER God, the desire of every human heart, You moved St. Augustine to seek restlessly for truth and peace. Touch our hearts with his burning desire for wisdom, for the Word made flesh. God of truth and justice, You taught Augustine to love unity and common life. Give us a share in his thirst for unity and make us one in mind and heart. God, our shepherd, You made Augustine faithful pastor of Your flock. Guide us, like him, to serve all people. As we make our way to Your Kingdom. God, in whom we find our rest, Renew in us the desire to follow Jesus and his servant Augustine. Keep us faithful to our promises until at last we find our rest in You. AMEN.