Alzheimer's/Parkinsons Flashcards
pathologic changes in Alzheimer disease
formation of neurofibrillary tangles and plaques, cortical atrophy, and neuronal (Cholinergic and glutamatergic) destruction and loss
drug therapy choices for cognitive symptoms of AD
cholinesterase inhibitors and memantine
cholinesterase inhibitor drugs
donepezil (Aricept)
rivastigmine (Exelon)
galantamine (Razadyne)
when would you switch agents in the cholinesterase inhibitor class of AD
if no effects is seen in 3-6mo or if patient experiences adverse effects
which cholinesterase inhibitor is approved for mild-mod AD and mild-mod Parkinson’s dementia
rivastigmine (Exelon)
titration of cholinesterase inhibitor drugs
recommended to titrate up to maximum tolerated dosage
which patients would you be cautious in prescribing cholinesterase inhibitors for AD
hx peptic ulcer disease and who currently take NSAIDs, hx or current seizure disorder
donepezil also causes insomnia and nightmares
contraindications for cholinesterase inhibitors for AD
anorexia neuroleptic malignant syndrome bradycardia peptic ulcer disease conduction abnormalities asthma/COPD seizure disorders
dos food effect the onset of action or absorption of memantine
no
agents for noncognitive symptoms of AD
antipsychotic drugs
benzodiazepines
antidepressants
typical antipsychotics used to manage agitation/psychosis in patients with AD
Risperidone (Risperdal)
olanzapine (Zyprexa)
typical BZDs used to manage anxiety or episodic agitation in AD
lorazepam (Ativan)
alprazolam (Xanax)
1st line therapy for AD
usually, donepezil but any cholinesterase inhibitor may be used. Severe AD may be offered Memantine as well
2nd line therapy for AD
different cholinesterase inhibitor
some providers may add vitamin E
following up with AD patients
q3-6mo
response to antipsychotics in AD
usually seen in the first day
what if marked decline in cognitive function is noted in the first 3-6 weeks after dc’ing cholinesterase inhibitors
consider restarting
patient education of donepezil
may be taken without regard to food
take in morning if it causes insomnia or nightmares
patient education on galantamine (Razadyne)
give without regard to food and should be slowly titrated
patient education on vitamin E for AD
report unusual bruising, blood in urine/stool, bleeding gums as it predisposes to bleeding
mech of action of vitmamin E for AD
an antioxidant that can stabilize free radicals and the damage they produce
herbal agnets used in tx of AD
ginko biloba (may interact with warfarin or ASA increasing risk of bleeding)
medications that may cause drug induced parkinsonism (DIP)
agents that deplete or antagonize dopamine (first-generation “typical” antipsychotics or neuroleptic drugs)
which antipsychotics are associated with lower rates of DIP
clozapine and quetiapine
other drugs that may cause DIP
metoclopramide, valproic acid, methyldopa, prochlorperazine
caffeine and PD (parkinson’s disease)
may be protective to dopaminergic neurons
high intake is associate with lower PD risk in women taking HRT
hallmark motor symptoms of PD
slowing movement (bradykinesia)
resting postural tremor
cogwheel rigidity
difficulty maintaining balance (postural instability)
mild-potency drugs for PD
anticholinergics
amantadine
MAO-B inhibitors
anticholinergic drugs used to tx PD
trihexyphenidyl
benztropine
specifically useful for symptom of drooling
discontinuation of anticholinergic drugs in PD
must be tapered as abrupt dc can exacerbate adverse effects
contraindications to anticholinergics for PD
narrow-angle glaucoma
benztropine is contraindicated in patients <3
anticholinergics and KCL
should be avoided d/t increased risk of ulcers
amantadine dosage in renal dysfunction
needs adjusted
amantadine and memantine
concomitant use has increased risk of QT prolongation and psychosis
indication for MAO-B inhibitors in PD
may delay need for levodopa by a few months but do not delay clinical progression of PD
MAO-B inhibitor drugs for tx of PD
selegiline
rasagiline
contraindications to MAO-B inhibitors
meperidine, methadone, propoxyphene, tramadol, St. John’s wort, cyclobenzaprine, dextromethorphan, other MAOBIs
additional contrindications with MAOBI selegiline
concurrent therapy with carbamazepine, SSRIs, SNRIs, clomipramine, imipramine
major adverse effect when MAOBIs are used with serotonergic drugs or tyramine-containing foods
serotonin syndrome
moderate potency drugs to tx PD
dopamine agonists
dopamine agonist drugs for tx of PD
pramipexole, ropinirole, rotigotine
contraindications for dopamine agonists in PD
elderly
high potency drugs for tx of PD
levodopa
catechol-O-methyltransferase inhibitors
what happens after several years of tx with levodopa
“wearing-off” syndrome where symptoms return prior to next dose
why is dopamine itself not used to tx PD
cannot cross blood-brain barrier
why is levodopa administered with carbidopa
carbidopa limits peripheral breakdown of levodopa allowing fourfold increase in circulating levodopa to cross blood-brain barrier and reduces N/V side effects
contraindications to levodopa/carbidopa
Narrow-angle glaucoma
carbidopa-levodopa interactions
avoid meals high in protein as it can reduce absorption
increase fluid/fiber intake as constipation reduces absorption as well
why are catechol-O-methyltransferase inhibitors (COMTIs) used in conjunction with levodopa
decrease “wearing-off” syndrome
COMTIs available drugs
entacapone
tolcapone
lab monitoring with COMT drugs (entacapone, tolcapone)
LFT q2-4wks for first 6mo and periodically thereafter
starting therapy for patients with mild motor symptoms in PD
MAOBI before trying a dopamine agonist or levodopa
starting drug therapy with moderate-severe impairment in PD
dopamine agonist or levodopa (DA is chosen over levodopa in the younger population)
considerations with mild-mod potency drugs for PD
anticholinergics are generally avoided
amantadine should be chosen over MAOBI in younger patients
MAOBI are favored over amantadine in the elderly and those with renal impairment
tx of depression in PD
typically pramipexole or venlafaxine
TCAs and DAs have been labeled as “likely efficacious”
tx psychosis in PD
clozapine and quetiapine have the most evidence for use
what other agents have been shown to reduce hallucinations in PD
donepezil rivastigmine (Exelon) ziprasidone
