Ner voussys drugs

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Ner voussys drugs

  1. 1. Cholinergic Drugs
  2. 2. Cholinergic Drugs Describe the cholinergic drug effects on major body systems. Discuss the nursing process related to the care of patients receiving cholinergic drugs for select problems.
  3. 3. Cholinergic Drugs Drugs that stimulate the parasympathetic nervous system (PSNS)  opposing system to the SNS  Known as: cholinergic agonists or parasympathomimetics  Mimic the effects of the PSNS neurotransmitter: acetylcholine (Ach) Two types of Receptors:  determined by: Location & Action once stimulated  Muscarinic receptors – recommended doses with desired effect  Nicotinic receptors – higher doses with undesirable effects
  4. 4. Cholinergic Drugs Mechanism of Action Direct-acting cholinergic agonists  Bind to cholinergic receptors, activating them Indirect-acting cholinergic agonists  Inhibit the enzyme acetylcholinesterase - preventing, which breaks down ACh - more ACh is available at the receptors  Reversible - Bind to cholinesterase for a period of minutes to hours  Irreversible - Bind to cholinesterase and form a permanent covalent bond  The body must make new cholinesterase to break these bonds
  5. 5. Cholinergic Drugs“rest and digest” system “SLUDGE”  Salivation  Lacrimation  Urinary incontinence  Diarrhea  Gastrointestinal cramps  Emesis
  6. 6. Cholinergic Drugs Drug Effects Stimulate intestine and bladder  Increased gastric secretions  Increased gastrointestinal motility  Increased urinary frequency Stimulate pupils  Constriction (miosis)  Reduced intraocular pressure Increased salivation and sweating Cardiovascular effects  Decreased heart rate  Vasodilation Respiratory effects  Bronchial constriction, narrowed airways
  7. 7. Cholinergic Drugs Drugs Bethanechol (Urecholine) – urinary retention Cevimeline (Evoxac) – Xerostomia Memantine (Namenda) – Alzheimer’s dementia Physostigmine (Antilirium) – reversal of anticholinergic drugs effects Pyridostigmine (Mestinon) – Myasthenia gravis
  8. 8. Cholinergic Drugs IndicationsDirect-acting drugs Reduce intraocular pressure Topical useful for glaucoma and intraocular surgery  pilocarpine
  9. 9. Cholinergic Drugs IndicationsDirect-acting drug—bethanechol (Urecholine) Increases tone and motility of bladder and GI tract Relaxes sphincters in bladder and GI tract, allowing them to empty Used to reverse postsurgical atony of the bladder and GI tract Oral dose or SC injection
  10. 10. Cholinergic DrugsIndications Indirect-acting drugs  Cause skeletal muscle contractions  Used for diagnosis and treatment of myasthenia gravis  Pyridostigmine (Mestinon) – Myasthenia gravis  Used to reverse neuromuscular blocking drugs/anesthesia  Used to reverse anticholinergic poisoning (antidote)  Examples: physostigmine (Antilirium)
  11. 11. Cholinergic DrugsIndicationsIndirect-acting drugs—cevimeline (Evoxac) Used to treat xerostomia (dry mouth) resulting from Sjögren’s syndrome
  12. 12. Cholinergic Drugs Adverse EffectsAdverse effects are a result of overstimulation of the PSNS Cardiovascular  Bradycardia, hypotension, conduction abnormalities (AV block and cardiac arrest) CNS  Headache, dizziness, convulsions Gastrointestinal  Abdominal cramps, increased secretions, nausea, vomiting Respiratory  Increased bronchial secretions, bronchospasm Other  Lacrimation, sweating, salivation, loss of binocular accommodation, miosis
  13. 13. Cholinergic DrugsInteractions  Anticholinergics, antihistamines, sympathomimetics  Antagonize cholinergic drugs, resulting in decreased responses  Other cholinergic drugs  Additive effects
  14. 14. Cholinergic Drugs Nursing Implications Assess for allergies, presence of GI or GU obstructions, asthma, peptic ulcer disease, or coronary artery disease Perform baseline assessment of vital signs and systems overview Medications should be taken as ordered and not abruptly stopped The doses should be spread evenly apart to optimize the effects of the medication Overdosing can cause life-threatening problems. Only physicians should adjust the dosages
  15. 15. Cholinergic Drugs Nursing Implications Encourage patients with myasthenia gravis to take medication 30 minutes before eating to help improve chewing and swallowing When cholinergic drugs are prescribed for Alzheimer’s disease, be honest with caregivers and patients that the drugs are for management of symptoms, not a cure Therapeutic effects of anti-Alzheimer’s drugs may not occur for up to 6 weeks
  16. 16. Cholinergic Drugs Nursing ImplicationsMonitor for therapeutic effects Alleviated signs and symptoms of myasthenia gravis In postoperative patients with decreased GI peristalsis, look for:  Increased bowel sounds  Passage of flatus  Occurrence of bowel movements In patients with urinary retention/hypotonic bladder, urination should occur within 60 minutes of bethanechol administration ALSO monitor for adverse effects
  17. 17. Drugs Affecting the Parasympathetic Nervous SystemParasympathetic Nervous System Neurotransmitter is ACH The receptors are called cholinergic receptors. Drugs that bind to cholinergic receptors and produced effects similar to ACH are referred to as cholinergic drugs.
  18. 18. Drugs Affecting the Parasympathetic Nervous System ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH Acetylcholinesterase
  19. 19. Drugs Affecting the Parasympathetic Nervous System Receptors Muscarinic Receptors Nicotinic Receptors N-1 N-2
  20. 20. Drugs Affecting the Parasympathetic Nervous System Nicotinic Receptors Nicotinic-I Receptors Nicotinic-II ReceptorsFound at ganglions of Found at Neuromuscular junction ofSympathetic and Parasympathetic Skeletal muscles.Post- ganglionic fibers
  21. 21. Drugs Affecting the ParasympatheticNervous System Ganglion, Nicotinic I receptor Sympathetic Fibers Pre-ganglionic Post-ganglionic Fiber Fiber Adrenergic Receptor Ganglion, Nicotinic I receptor Parasympathetic Fibers Pre-ganglionic Fiber Post-ganglionic Fiber Muscarinic Receptors Somatic Fibers Nicotinic II Receptors
  22. 22. Drugs Affecting the Parasympathetic Nervous SystemNicotine Alkaloid obtained from tobacco. Stimulate the NI receptors at low doses. Block the NII receptors at high doses.
  23. 23. Drugs Affecting the ParasympatheticNervous System Nicotinic I Drugs Ganglionic Ganglionic Stimulants Blockers
  24. 24. Drugs Affecting the Parasympathetic Nervous SystemMuscarinic Receptors Found at the parasympathetic postganglionic nerve endings Drugs that act like ACH at these receptors are referred to as cholinergic or muscarinic drugs. Drugs that block ACH at the muscarinic receptors are referred to as anticholinergic or antimuscarinic drugs.
  25. 25. Drugs Affecting the Parasympathetic Nervous System Parasympathetic Drugs Cholinergic Anti-cholinergic Drugs Drugs
  26. 26. Drugs Affecting the Parasympathetic Nervous System Cholinergic Drugs Direct Acting Indirect Acting Cholinergic Drugs Cholinergic Drugs
  27. 27. Drugs Affecting the Parasympathetic Nervous System Direct Acting Cholinergic Drugs  Bind to muscarinic receptors.  Produces ACH like effect.  Slowly inactivated by acetylcholinesterase.
  28. 28. Drugs Affecting the Parasympathetic Nervous System Pharmocological Effects  Increase GI secretion and motility  Increase in genitourinary activity.  Bronchoconstriction
  29. 29. Drugs Affecting the Parasympathetic Nervous System Pharmocological Effects  Miosis  Vasodilatation (lower BP)  Decrease heart rate.
  30. 30. Drugs Affecting the Parasympathetic Nervous System Direct Acting Main Use Acetylcholine Miotic Bethanecol Nonobstructive urinary retention Carbachol Treatment of glaucoma Methacholine Miotic Pilocarpine Treatment of glaucoma
  31. 31. Drugs Affecting the Parasympathetic Nervous System Indirect Acting Cholinergic Drugs (Anticholinesterases) Reversible Irreversible Inhibitors Inhibitors
  32. 32. Drugs Affecting the Parasympathetic Nervous System ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH ACH Acetylcholinesterase Anticholinesterases
  33. 33. Drugs Affecting the Parasympathetic Nervous System Reversible Inhibitors  Blocks cholinergic and nicotinic receptors.  Use in the diagnosis and treatment of myasthenia gravis.
  34. 34. Drugs Affecting the Parasympathetic Nervous System Irreversible Inhibitors  Derivatives of organophosphate compounds.  Widely used as insecticides, pesticides and chemical warfare agents.  Long duration of action
  35. 35. Drugs Affecting the Parasympathetic Nervous SystemClinical Use Topical use in glaucoma Treatment of myasthenia gravis Treatment of urinary retention and intestinal stasis
  36. 36. Drugs Affecting the Parasympathetic Nervous SystemClinical Use Treatment of Alzheimer’s disease. Antidote to skeletal muscle blockers. Antidotes to anticholinergic drug poisoning.
  37. 37. Drugs Affecting the Parasympathetic Nervous System Indirect-Acting Cholinergic Drug Reversible Irreversible Ambenonium Isoflurophate Edrophonium Neostigmine Physostigmine Pyridostigmine
  38. 38. Drugs Affecting the Parasympathetic Nervous SystemAdverse and Toxic Effect Nausea Vomiting Diarrhea Blurred vision
  39. 39. Drugs Affecting the Parasympathetic Nervous SystemAdverse and Toxic Effect Excessive sweating Muscular tremors Bronchoconstriction Bradycardia
  40. 40. Drugs Affecting the Parasympathetic Nervous SystemAdverse and Toxic Effect Hypotension Mucular paralysis Respiratory arrest
  41. 41. Drugs Affecting the Parasympathetic Nervous SystemCholinergic Crisis Excessive drug dosage in patients with myasthenia gravis. High concentration of ACH causes excessive stimulation of the muscarinic receptors. High concentration of ACH causes blockade of nicotinic receptor.
  42. 42. Drugs Affecting the Parasympathetic Nervous SystemTreatment Stop anticholinesterase drug administration. Give atropine to block the effect of excess muscarinic stimulation
  43. 43. Drugs Affecting the Parasympathetic Nervous SystemCholinergic Crisis Excessive exposure to sprays containing derivatives of irreversible anticholinesterase. High concentration of ACH causes excessive stimulation of the muscarinic receptors. High concentration of ACH causes blockade of nicotinic receptor.
  44. 44. Drugs Affecting the Parasympathetic Nervous SystemTreatment Remove person from the exposure. Give Pralidoxime to reactivate the anticholinesterase enzyme. Give atropine to block the effect of excess muscarinic stimulation
  45. 45. Drugs Affecting the Parasympathetic Nervous SystemAnticholinergic Drugs Binds to muscarinic receptors. Act by competitive antagonism of ACH. Prototype drugs: Belladonna alkaloids, atropine and scopolamine
  46. 46. Drugs Affecting the Parasympathetic Nervous SystemPharmacological Action Increase heart rate. Increase the secretions of the respiratory tract and may cause bronchoconstriction. Reduce salivary and GI tract. Inhibit urinary peristalsis and voiding of urine.
  47. 47. Drugs Affecting the Parasympathetic Nervous SystemPharmacological Action Depressant effects on the CNS causing drowsiness and sedation. At high doses cause both stimulation and depression of the CNS At toxic doses excitation, delirium, hallucination and profound CNS depression leading to respiratory arrest and death.
  48. 48. Drugs Affecting the Parasympathetic Nervous System Ocular Effect  Mydriasis  Cycloplegia  Increases Intraocular pressure.
  49. 49. Drugs Affecting the Parasympathetic Nervous SystemAdverse and Toxic Effect Cause by excessive blockage of the Parasympathetic Nervous System. Dry mouth. Visual disturbances Urinary retention Constipation.
  50. 50. Drugs Affecting the Parasympathetic Nervous SystemAdverse and Toxic Effect Dryness of the skin Flushing Hyperpyrexia CNS stimulation and depression
  51. 51. Drugs Affecting the Parasympathetic Nervous System Anticholinergic DrugsBelladonna Alkaloids Synthetic Drugs Atropine Semisynthetic Drug Diclyclomine Scopolamine Isopropamide Hyoscyamine Homatropine Propantheline Methantheline
  52. 52. Drugs Affecting the SympatheticNervous System Release Adrenergic Receptor NE NE NE MAO NE NE Involuntary Muscle Membrane Metabolism Reuptake NEAdrenergic nerve ending
  53. 53. Drugs Affecting the SympatheticNervous System Adrenergic Receptors Alpha Beta Receptors Receptors Beta 1 Beta 2 Receptors Receptors
  54. 54. Drugs Affecting the SympatheticNervous System Alpha-adrenergic Receptors  Found predominantly on smooth muscle membrane.  When stimulated by NE or EPI produce contraction.  Produces vasoconstriction of most blood vessels.
  55. 55. Drugs Affecting the SympatheticNervous System Beta-adrenergic Receptors  Found on both cardiac and some smooth muscle membranes.  In the heart, beta 1 receptors predominates.  When stimulated by NE or EPI, they increase heart rate and force of contraction.
  56. 56. Drugs Affecting the SympatheticNervous System Beta-adrenergic Receptors  Found on smooth muscle in the bronchus and smooth muscles of blood vessels supplying muscle and the heart.  Stimulated with EPI result in relaxation.
  57. 57. Drugs Affecting the SympatheticNervous System Beta-adrenergic Receptors  In smooth muscle, beta 2 receptors predominates.  When stimulated by EPI, they produces muscle relaxation.  Found in smooth muscles of blood vessels supplying skeletal muscle and the coronary arteries.  Found on smooth muscle in the bronchial tree.
  58. 58. Drugs Affecting the SympatheticNervous System Beta 1 Receptors Found on smooth muscle in the heart Increase heart rate and force of contraction.
  59. 59. Drugs Affecting the SympatheticNervous System Beta 2 Receptors Found on smoothFound on smooth muscle muscle in theof blood vessels supplying bronchial tree.skeletal muscle and the heart. Vasodilatation. Bronchodilation.
  60. 60. Drugs Affecting the SympatheticNervous System Sympathetic Drugs Sympathomimetic Sympatholytic Drugs Drugs
  61. 61. Drugs Affecting the SympatheticNervous System Sympathomimetic Drugs Alpha-adrenergic Beta- adrenergic Selective Beta 1 Selective Beta 2 Adrenergic. Adrenergic.
  62. 62. Drugs Affecting the SympatheticNervous System Alpha-adrenergic Drugs  NE prototype  Most important clinical effect is contraction of smooth muscles.  Vasoconstriction of most blood vessels leading to increase in blood pressure.  Contraction of sphincter muscles.
  63. 63. Drugs Affecting the Sympathetic Nervous System Contraction of Sphincter Muscles GI tract Urinary Tract EyesInhibits movement of Restricts passage Mydriasisintestinal contents of urine.
  64. 64. Drugs Affecting the SympatheticNervous System Alpha-adrenergic Drugs Clinical Indications  Hypotensive states  Decongestion  Pupillary dilation
  65. 65. Drugs Affecting the SympatheticNervous System Adverse Effects  Hypertensive crisis  Cerebral hemorrhage  Cardiac arrhythmias  Irritation of the nasal sinuses or eye.
  66. 66. Drugs Affecting the SympatheticNervous System Drug Main UseEpinephrine To increase BPNorepinephrine To increase BPPseudoephedrine Nasal decongestionTetrahydrozoline Ophthalmic decongestion
  67. 67. Drugs Affecting the SympatheticNervous System Beta-adrenergic Drugs  Stimulation of the heart  Bronchodilation  Relaxes uterine smooth muscle
  68. 68. Drugs Affecting the SympatheticNervous System Drugs Classification Main UseEpinephrine Alpha, Beta-1 Vasopressor, Cardiac and Beta-2 stimulant, bronchodilator.Isoproterenol Beta-1 and Beta- Cardiac stimulant, 2 bronchodilator.Albuterol Beta-2 Bronchodilator.Ritodrine Beta-2 Arrest preterm labor.
  69. 69. Drugs Affecting the SympatheticNervous System Epinephrine  DOC for allergic reactions  Use in combination with local anesthetics.  Used as a cardiac stimulant in emergencies.  Use in the treatment of asthma.
  70. 70. Drugs Affecting the SympatheticNervous System Adverse Effects  CNS stimulation – tremor, restlessness, anxiety (beta effect)  Over-stimulation of the heart (beta 1 effect)  Lower blood pressure (beta 2 effect)
  71. 71. Drugs Affecting the SympatheticNervous System Dopamine  Neurotransmitter in the brain.  Precursor in the synthesis of NE  Stimulates dopaminergic, beta-1 and alpha- receptors.  Use as a drug.  Dobutamine similar to dopamine but with more Beta-1 effect.
  72. 72. Drugs Affecting the SympatheticNervous System NE NE NE MAO Tyrosine DOPA Dopamine NE NE
  73. 73. Drugs Affecting the SympatheticNervous System DOPAMINE RECEPTORS EFFECTS DOSE STIMULATEDLow dose Stimulate dopaminergic Increased renal blood flow receptors in the renal and and vasodilatation. mesenteric blood vessels.Moderate dose Stimulates beta-1 Increase myocardial receptors in the heart. contractility.Higher dose Stimulate alpha-receptors Produces vasoconstriction.
  74. 74. Drugs Affecting the SympatheticNervous System Alpha-adrenergic blocking drugs  Binds to Alpha receptors  Antagonizes the effects of NE and EPI  Leads to a decrease in sympathetic response  Resulting in vasodilatation and thus decrease in BP.
  75. 75. Drugs Affecting the SympatheticNervous System Alpha-adrenergic blocking drugs. Clinical Indications  Treatment of hypertension.  Vasodilator in treatment of Raynaud’s disease.  Diagnosis of Pheochromocytoma.
  76. 76. Drugs Affecting the SympatheticNervous System Alpha-adrenergic blocking drugs. Adverse Effects  Constriction of pupils  Increased GI activity  Nasal congestion  Reflex tachycardia ( if BP is lowered too much).
  77. 77. Drugs Affecting the SympatheticNervous System Drugs Main UseDoxazosin Treatment of HypertensionPrazosin Treatment of HypertensionPhentolamine Diagnosis of pheochromocytoma. Treatment of vascular disease.
  78. 78. Drugs Affecting the SympatheticNervous System Beta-adrenergic blocking drugs.  Binds to beta receptors  Antagonizes the effects of NE and EPI  Leads to a decrease in sympathetic response.  Resulting in decrease heart rate and force of contraction.
  79. 79. Drugs Affecting the SympatheticNervous System Beta-blocking Drugs Non-selective Selective Beta-1
  80. 80. Drugs Affecting the SympatheticNervous System Nonselective Blockers Main UseLabetalol HypertensionNadolol Hypertension, Angina PectorisPindolol HypertensionPropanolol Hypertension, Angina Pectoris, arrhythmhias, migraineTimolol Hypertension, post myocardial infarction.
  81. 81. Drugs Affecting the SympatheticNervous System Selective Blockers Main UseAcebutolol Hypertension, ventricular arrhythmias.Atenolol Hypertension, Angina PectorisBisoprolol HypertensionEsmolol Supraventricular tachycardiaMetoprolol Hypertension, Angina Pectoris
  82. 82. Drugs Affecting the SympatheticNervous System Propranolol  Decrease heart rate  Decrease force of contraction  Decrease rate of conduction  Resulting decrease in effort and work of the heart causes a decrease in oxygen consumption.
  83. 83. Drugs Affecting the SympatheticNervous System Oral and iv preparation Drug is carried directly to the liver by the portal system. Significant first pass metabolism. Lipid soluble and passes into the brain. Causes CNS sedation, depression and decreased central sympathetic activity.
  84. 84. Drugs Affecting the SympatheticNervous System  Used in the treatment of angina, and various cardiac arrhythmia.  Adverse effects include nausea, vomiting and diarrhea, bradycardia with resulting reduced cardiac function, bronchoconstriction.  Most serious drug interactions involve therapy of beta blockers with other drugs that decrease cardiac function (cardiac glycosides, anti-arrhythmic drugs and calcium blockers).
  85. 85. Drugs Affecting the SympatheticNervous System Adrenergic neuronal blockers  Drugs that interfere with the formation and or storage of NE  Alpha-methyl dopa  Reserpine  Guanethidine
  86. 86. Drugs Affecting the SympatheticNervous System Reserpine NE NE NE MAO Tyrosine DOPA Dopamine NE NE Guanethidine Alpha-methyl dopa
  87. 87. Drugs Affecting the SympatheticNervous System Drugs Mechanism of Action Main UseAlpha-methyl dopa Blocks formation of Treatment of Dopamine hypertensionReserpine Depletes NE storage Treatment of granule hypertensionGuanethidine Block release of NE Treatment of and depletes NE hypertension storage granule

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