Parkinson's & Alzheimer's

• Parkinson's Disease


  Three symptoms: involuntary tremors of the limbs, rigidity of muscles, and slowness of movement
• Anticholinergics


  • Reduce rigidity and some tremors in Parkinson's disease but have minimal effect on bradykinesia
  • Parasympatholytics that inhibit the release of acetylcholine
  • Used to treat drug-induced parkinsonism or pseudoparkinsonism
• Anticholinergics used for Parkinson's disease


  • Trihexyphenidyl hydrochloride
  • Benztropine mesylate
• Dopaminergics


  • Levodopa was effective in diminishing Parkinson's symptoms and increasing mobility, but only about 1% reaches the brain as the rest is converted to dopamine in the peripheral nervous system
  • Carbidopa inhibits the enzyme dopa decarboxylase in the peripheral nervous system, allowing more levodopa to reach the brain
• Dopamine Agonists


  Stimulate the dopamine receptors, e.g. amantadine hydrochloride and bromocriptine mesylate

  Amantadine may initially improve Parkinson's symptoms but tolerance develops

  Bromocriptine is more effective than amantadine but not as effective as carbidopa-levodopa, used for patients who don't tolerate carbidopa-levodopa
• Dopamine Agonists


  Other dopamine agonists, also called dopaminergics, stimulate the dopamine receptors
• Amantadine hydrochloride


  An antiviral drug that acts on the dopamine receptors, may be taken alone or in combination with carbidopa-levodopa or an anticholinergic drug, initially produces improvement in symptoms but this is not sustained due to drug tolerance
• Bromocriptine mesylate


  Acts directly on dopamine receptors in the CNS, cardiovascular system, and GI tract, more effective than amantadine and anticholinergics but not as effective as carbidopa-levodopa, given to patients who do not tolerate carbidopa-levodopa
• Monoamine Oxidase B Inhibitors (MAOI)

  The enzyme MAO-B causes catabolism (breakdown) of dopamine, selegiline inhibits MAO-B and thus prolongs the action of levodopa, may be ordered for patients newly diagnosed to delay carbidopa-levodopa therapy
• MAOI Drugs


  • Selegiline hydrochloride
  • Rasagiline
• Catechol-O-Methyltransferase Inhibitors (COMT Inhibitors)

  The enzyme COMT inactivates dopamine, when taken with a levodopa preparation, COMT inhibitors increase the amount of levodopa concentration in the brain
• COMT Inhibitor drugs


  • Tolcapone
  • Entacapone
• Contraindications


  Anticholinergics or any drugs that have anticholinergic effects are contraindicated for patients with glaucoma, those with severe cardiac, renal, or psychiatric health problems should avoid levodopa drugs, patients with chronic obstructive lung diseases can have dry, thick mucous secretions caused by large doses of anticholinergic drugs
• Alzheimer Disease


  An incurable dementia illness characterized by chronic, progressive neurodegenerative conditions with marked cognitive dysfunction, onset usually occurs between 45 and 65 years of age
• Stages of Alzheimer Disease

  • Mild stage (early-stage): memory lapses, difficulty concentrating, misplaces objects, forgets what was just read, increased problems with planning and organizing
  • Moderate stage (middle-stage): irritable, moody, withdrawn, display frustration and anger, have personality and behavioral changes, changes in sleep pattern, confusion regarding what day it is, inability to recall personal information, may wander and become lost, inability to perform routine tasks, difficulty controlling bowels/bladder
  • Severe stage: forgets recent experiences and previously known individuals, requires high levels of assistance with activities of daily living, inability to respond to their environment or converse, inability to walk, sit, or swallow, becomes vulnerable to infections, especially pneumonia
• Acetylcholinesterase/Cholinesterase Inhibitors


  FDA-approved medications to treat Alzheimer disease symptoms, increase cognitive function for patients with mild to moderate Alzheimer disease
• Rivastigmine


  An AChE inhibitor prescribed to improve cognitive function for patients with mild to moderate Alzheimer disease, increases the amount of ACh at the cholinergic synapses, tends to slow the disease process and has fewer drug interactions than donepezil
• Acetylcholinesterase Inhibitors for Alzheimer Disease


  • Donepezil
  • Rivastigmine
  • Memantine
  • Galantamine