Parkinson and Alzheimer's Flashcards
(16 cards)
What is the pathology of Parkinson disease? What are the TRAP major symptoms?
Pathology: neurons diet in the basal ganglia which means less dopamine is being produced -> less instructions to the brain -> movement problems
T - tremor (when resting)
R - rigidity
A - akinesia/bradykinesia (lack of/slow start in movement)
P - postural instability
What is the preferred drug treatment for Parkinson disease?
Replace dopamine through:
- drug that mimics dopamine (ex. dopamine agonist)
- drug that increases dopamine (ex. levodopa +/- COMT)
- give other drugs for specific symptoms (ex. anticholinergics for resting tremor)
What is the MOA of carbidopa/levodopa? What is the starting dose? What is 1 contraindication? What are some side effects? How much carbidopa is required?
MOA - levodopa is a precursor of dopamine, carbidopa prevents peripheral metabolism of levodopa
IR starting dose: 25/100mg PO TID
**need to titrate cautiously and taper off
Contraindication: do not use with non-selective MAO inhibitors w/in 14 days
Side effects:
- nausea
- dizziness
- orthostasis
- dyskinesias
- hallucinations/psychosis
- can cause brown, black, or dark urine
- d/c if positive Coombs test
- unusual sexual urges, priapism
Notes:
- 70-100mg of carbidopa per day is required to inhibit the enzyme
What is the MOA of COMT inhibitors? What are 3 medications in this calss?
MOA - increase the duration of action of levodopa by inhibiting COMT (prevents peripheral conversion of levodopa). These should ONLY be used WITH levodopa
- entacapone (200mg PO w/ each dose)
- opicapone
- tolcapone
What are 3 of the dopamine agonists? What are 4 warnings? What is required when discontinuing these medications? How do you apply the patch?
- pramipexole (Mirapex, Mirapex ER)
- ropinirole
- rotigotine - patch
Warnings
1. somnolence
2. orthostasis
3. hallucinations
4. dyskinesias
MUST titrate/taper to avoid withdrawal symptoms. Do NOT abruptly discontinue.
Patch: apply once daily. Do not use the same site for at least 14 days.
- remove the patch before an MRI
What dopamine agonist is used as a “rescue” during “off”periods? What is 1 contraindication, 2 side effects, and what medication is given for emesis prevention?
apomorphine (SC injection)
*must be started with a test dose in a medical office
Contraindication: do not use with 5-HT3 antagonist (ondansetron) due to severe hypotension and loss of consciousness
Side effects:
- severe nausea/vomiting
- hypotension
Emesis prevention: give trimethobenzamide (Tigan)
What is amantadine’s MOA? What are 2 warnings and 3 side effects?
MOA - blocks dopamine reuptake
Warnings
1. somnolence
2. psychosis
Side effects
- dizziness
- orthostatic hypotension
- livedo reticularis (reddish skin mottling)
What are some selective MAO-B inhibitors and how do they work? At what time of day should you take selegiline? What are 2 contraindications and 2 warnings?
- selegiline (Zelapar [ODT])
- rasagiline (Azilect)
- safinamide (Xadago)
Selegiline is activating so it should NOT be taken at bedtime.
Contraindications
1. no not use in combination w/ other MAO inhibitors, opioids, SNRIs, TCAs, or others
2. Xadago is contraindicated in severe liver impairment
Warnings
- serotonin syndrome
- hypertension
Why would benztropine be used in parkinson disease?
benztropine is an anticholinergic, so it can be used to help with tremors
What is the pathophysiology of Alzheimer’s disease?
Neuropathologic changes, including amyloid beta plaques, and tau tangles, that lead to the death of cholinergic neurons, resulting in decreased acetylcholine
What are 3 classes of drugs that can worsen dementia?
Antipsychotics (ex. aripiprazole, chlorpromazine)
CNS depressants (ex. barbiturates, benzodiazepines, opioids, hypnotics, skeletal muscle relaxants)
Anticholinergic drugs (ex. antiemetics, antihistamines, central anticholinergics, peripheral anticholinergics, tricyclic antidepressants)
What natural products may be used to slow the rate of decline for pts with mild to moderate dementia?
Vitamin E (2000 IU daily) may minimally slow the rate of decline
Acetyl-L-carnitine, ginkgo biloba, and vinpocetine are also used
What is the primary drug treatment for Alzheimer’s?
Mild to moderate: 1st line -> acetylcholinesterase inhibitors (ex. donepezil, rivastigmine, galantamine)
Moderate to severe: memantine may be added or used alone, but combination treatment is more effective
Recommended to d/c drug therapy if dementia has progressed to the point where drug therapy lacks clinical benefit or side effects become intolerable.
Mild Alzheimer’s: amyloid beta-directed antibodies - role in treatment not well defined
- adacanumab (Aduhelm)
- lecanemab (Leqembi)
Which antipsychotic is FDA approved for the treatment of agitation associated with dementia due to Alzheimer’s disease?
Brexpiprazole (Rexulti)
antipsychotics may be used for agitation and psychosis if the pt remains in significant distress or poses harm to themselves or others, despite non-pharm interventions.
d/c antipsychotic when possible due to side effects and boxed warning for increased risk of death in elderly patients
What is the MOA of acetylcholinesterase inhibitors? What are the brand names of donepezil (3) and rivastigmine? What are 3 warnings, 1 side effect, and 4 notes about this class?
MOA - inhibit centrally-active acetylcholinesterase, the enzyme responsible for hydrolysis of acetylcholine. This increases acetylcholine
Donepezil
- Aricept (ODT, tablet)
- Adlarity (weekly patch)
- Namzaric (donepezil + memantine)
Rivastigmine (Exelon, daily patch)
Warnings
1. cardiac effects (inc bradycardia)
2. Donepezil: QT prolongation
3. GI effects (nausea, vomiting, diarrhea)
Side effect: insomnia
Notes
- donepezil is dosed qHS to decrease nausea. If insomnia occurs, morning dosing may be preferred
- store Adlarity patch in the refrigerator
- remove Exelon patch prior to MRI
- is stable on donepezil 10mg, can switch to Namzaric
What is the MOA of memantine? What are 3 side effects? Can you crush or chew the ER capsule?
Memantine (Namenda)
Memantine + donepezil (Namzaric)
MOA - NMDA receptor blocker. Prevents glutamate from binding to the NMDA receptor and causing overstimulation and neuronal death.
Side effects
- dizziness
- confusion
- headache
Notes
- no not crush or chew the ER capsule or Namzaric. The capsule can be opened and sprinkled on applesauce
