Neuro Degeneration (Ch20) PDF

Chapter 20 Medications for Degenerative Neurological Disorders 1  20.1 Identify the most common degenerative diseases of the central nervous system. 20.2 Describe symptoms of Parkinson dise...

Chapter 20 Medications for Degenerative Neurological Disorders 1  20.1 Identify the most common degenerative diseases of the central nervous system. 20.2 Describe symptoms of Parkinson disease. 20.3 Explain the neurochemical basis for Learning Parkinson disease, focusing on the roles of dopamine and acetylcholine in the brain. Outcome 20.4 Describe the nurse’s role in the pharmacologic management of Parkinson s (1 of 2) disease and Alzheimer disease. 20.5 Describe symptoms of Alzheimer disease and explain theories about why these symptoms develop. 20.6 Explain the goals of pharmacotherapy for Alzheimer disease and the efficacy of existing medications.  20.7 Describe the signs and basis for development of multiple sclerosis symptoms. 20.8 Categorize drugs used in the treatment of Alzheimer disease, Parkinson disease, and multiple sclerosis based on Learning their classification and mechanism of action. Outcome 20.9 For each of the drug classes listed in Drugs at a Glance, know representative s (2 of 2) drug examples, and explain their mechanisms of action, primary action, and important adverse effects. 20.10 Use the nursing process to care for patients receiving pharmacotherapy for degenerative diseases of the central nervous system. Degenerat ive Diseases of the Parkinson’s Disease Nervous Multiple Sclerosis System Alzheimer’s Disease 4  Parkinson’s Disease One of the most common degenerative CNS disease Progressive loss of dopamine Symptoms: Tremors Muscle rigidity Bradykinesia (difficulty chewing, swallowing, speaking) Postural instability Affective flattening 5  Cause of Symptoms Degeneration and destruction of dopamine-producing neurons Affect balance, posture Affect muscle tone, involuntary movement Absence of dopamine allows acetylcholine stimulation Ach Dopamine 6  Health Proble Primarily affects muscle movement Patients often experience other health ms in issues: Anxiety, depression Parkins Sleep disturbances on Dementia Autonomic nervous system Patient disturbances (e.g., difficulty urinating) s Drug Therapy for Parkinsonism Restores dopamine function Blocks acetylcholine Avoid extrapyramidal side effects (EPS)  Antiparkinsonism Agents Restore balance of dopamine and acetylcholine in brain Dopaminergic drugs Levodopa (Larodopa), with carbidopa (Sinemet) Catechol-O-Methyl Transferase (COMT) Inhibitors Anticholinergics (cholinergic blockers) Used in early stages Examples Benztropine mesylate (Cogentin) Triexyphenidyl hydrochloride (Artane) 9  Dopaminergic Agents Prototype drug: levodopa, carbidopa Mechanism of action: Increases biosynthesis of dopamine within nerve terminals Primary use: to restore dopamine function or stimulate dopamine receptors within the brain Adverse effects: dizziness, light-headedness, sleep dysfunction, fatigue, nausea, vomiting, constipation, orthostatic hypotension, dystonia, dyskinesia 10  Anticholinergic Agents Prototype drug: benztropine mesylate (Cogentin) Mechanism of action: block acetylcholine; inhibit overactivity in brain Primary use: in early stages of disease Adverse effects: dry mouth, blurred vision, photophobia, urinary retention, constipation, tachycardia, glaucoma 11 Anticholinergics - Patient Teaching Relieve dry mouth with frequent drinks or sugarless hard candy Take with food or milk to prevent GI upset Avoid alcohol Wear dark glasses; avoid bright sunlight Do not stop taking abruptly Teach signs and symptoms of overdose Severe nausea/vomiting, sweating, salivation, hypotension Bradycardia, convulsions, increased muscle weaknesses (including respiratory muscles) 12  Multiple Sclerosis Inflammatory disorder causing demyelination of neurons in CNS Destruction of axons impairs ability of nerves to conduct electrical impulses Progressive weakness, visual disturbances Mood alterations, cognitive deficits 13 Drug Therapy for MS Therapies include: Biological response modifiers Immunosuppressives Steroids Antispasmodic drugs Adjunctive treatment of symptoms 14  Immunomodulators Two categories Interferon beta (Avonex, Rebif, Betaseron) Glatiramer acetate (Copaxone) Synthetic protein that simulates myelin basic protein Reduce symptoms and decrease lesions Adverse Effects: flu like s/s (headache, fever, chills, muscle aches), anxiety, injection site irritation 15  Immunosuppressants Used for progressive-relapsing MS patients Mitoxantrone (Novantrone) Primarily a chemotherapeutic drug; toxicity is concern Adverse Effects: toxicity, hair loss, GI discomfort, allergic symptoms, blue-green tint to urine 16  Second most common degenerative disease of C N S responsible for 70% of all Alzheimer dementia ’s Progressive loss of brain function: Disease Memory loss, confusion, dementia Mainly affects people over the age of 50 17  Cause of most dementia unknown; associated with cerebral atrophy Alzheime Possible causes: Genetic factors (10% of r Disease cases) Chronic inflammation, excess free radicals (AD) Environmental factors Immunologic factors Nutritional factors Viruses  Struct Consists of: Amyloid plaques Neurofibrillary tangles ural Changes found during autopsies Structural changes cause loss in Damag number and function of neurons Symptoms result from progressive e in damage to neurons in hippocampus Hippocampus: learning and memory Brain Requires acetylcholine as neurotransmitter Sympto Impaired memory and judgment ms of Confusion and disorientation Inability to recognize family and Alzhei friends Aggressive behavior mer Depression Psychoses, including paranoia Diseas and delusions Anxiety e Goals of Pharmacotherapy for Alzheimer’s Disease 1 2 3 4 5 Slow Slow Improve Improve Improve memory dementia activities behavior cognition loss symptoms of daily living Efficacy of Drug Therapy No cure Intensify effect of acetylcholine at cholinergic receptor Drugs have modest efficacy Ineffective in late stages Cholinester ase Route and Adult Dose (max dose where Adverse Drug indicated) Effects Inhibitors donepezil PO: 5–10 m g at bedtime Headache, (Aricept) PO (extended release): 8 m dizziness, Prevent breakdown of galantamin g once daily and gradually insomnia, e increase to 16–24 mg/day nausea, acetylcholine: (Razadyne) PO: Start with 1.5 m g bid diarrhea, Enhance with food; may increase by vomiting, rivastigmine 1.5 m g bid every 2 wk if muscle transmission in (Exelon) tolerated; target dose 3–6 cramps, cholinergic neurons mg bid (max: 12 m g bid) anorexia, Slow progression of A D Exelon Patch: initial dose abdominal pain one patch 4.6 m g/24 h once Examples: daily; maintenance dose Hepatotoxicity, one patch 9.5 m g/24 h once renal toxicity, daily bradycardia, heart block, extreme weight loss Cholinesterase Inhibitors Prototype drug: donepezil (Aricept) Mechanism of action: to prevent breakdown of acetylcholine; enhance transmission in neurons Primary use: slow progression of the disease Adverse effects: nausea/vomiting; less commonly dizziness and headache, abnormal dreams, irritability, darkened urine Administration Alerts Give medication prior to bedtime. Medication is most effective when given on a regular schedule. Pregnancy category C. Adjunct A D Medicines Atypical antipsychotic agents Anxiolytics Mood stabilizers  Disease Description Alzheimer Progressive loss of brain function characterized disease by memory loss, confusion, and dementia Table 20.1 Major Amyotrophic A degenerative disease of the motor neurons Degenerative lateral sclerosis characterized by weakness and atrophy of Diseases of (Lou Gehrig disease) skeletal muscles; symptoms usually begin during middle age and progressively worsen the Central Nervous Multiple Demyelination of neurons in the C NS, resulting System sclerosis in progressive weakness, visual disturbances, mood alterations, and cognitive deficits Parkinson Progressive loss of dopamine in the C NS, disease causing tremor, muscle rigidity, and abnormal movements and posture  Drug class Administration What to Side effects Know Nursing interventions Know vocabulary terms 27