Chapter 31 Anti-Parkinson Agents

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Parkinson’s Disease A neurological disorder characterized by:  Muscle tremors  Muscle rigidity  Lack of coordination  Drooling  Shuffling gait  Postural changes (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Parkinson’s Disease Imbalance of dopamine and acetylcholine levels in the brain Levels of other neurological chemical decrease:  Gamma-aminobutyric acid (GABA)  Serotonin  Norepinephrine (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Classes of Anti-Parkinson Agents Dopaminergic agents Anticholinergic agents Catechol-O-methyltransferase inhibitors

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Levodopa Dopaminergic agent Most effective drug treatment Acts peripherally Rapidly converts to dopamine Symptoms subside or disappear (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Levodopa Therapeutic effects  Therapeutic intensity varies  Dosage dependent Adverse effects  Nausea and vomiting  Orthostatic hypotension  Cardiac arrhythmias (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Carbidopa/Levodopa (Sinemet) Carbidopa prevents levodopa from being broken down in the peripheral circulation Improves neurological-skeletal muscle activity Combining these agents reduces the required Levodopa dose by 25%  Given in Carbidopa, 10 mg / Levodopa,100 mg dose

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Amantadine (Symmetrel) Treats viral disorders such as influenza Acts as an anti-Parkinson agent; it exerts an additive effect on Levodopa  Increases CNS dopamine concentration

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Anticholinergic Agents Reduces excessive cholinergic brain activity  Example: trihexyphenidyl (Artane)  Used for clients with minimal symptoms  Adjunct with other agents Caution: narrow-angle glaucoma (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Anticholinergic Agents Apomorphine (Apokyn)  Morphine-like substance  Old, but new  No analgesic or addictive qualities  Increases dopamine activity (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Newest class of anti-Parkinson drug agents Treats clients with history of poor response to levodopa  Sustains dopaminergic levels  Brain remains stimulated (continues) Catechol-O-Methyltransferase Inhibitors

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Catechol-O-Methyltransferase Inhibitors Adverse effects  Liver failure  Dyskinesia  Orthostatic hypotension  Dystonia  Somnolence  GI irritation (continued)