neurological condtions Flashcards
Pathophysiology of Parkinson’s
less dopamine-> less instructions to the brain -> movement problems (called TRAP major symptoms)
TRAP
Tremor: when resting
Rigidity: in legs, arms, trunk, and face (mask-like face)
Akinesia/bradykinesia: lack of/slow start in movement
Postural instability: imbalance, falls
dopamine-blocking drugs that can worsen PD
- Phenothiazines (prochlorperazine) used for psychosis, nausea, agitation
- Butyrophenones (haloperidol, droperidol) used for psychosis and behavior disorder or nausea
- first and second gen antipsych (risperidone at higher dose, paliperidone); lowest risk is quetiapine
- metoclopramide, a renally-cleared drug that can accumulate in elderly pt
PD pt also depresssion
Depression common in PD pts
concerns w/ SSRI and SNRI but TCAs (secondary os desipramine and nortriptyline), and dopamine agonists like pramipexole provide antidepressants effects
quetiapine in PD
quetiapine is preferred in psychosis PD pts
low risk of movement disorders but can cause metabolic complications
clozapine has a low risk of worsening movement disorders but has a high risk of seizures and agranulocytosis
hallucinations and delusions in PD
pimavanserin (Nuplazid)
rapid withdrawal of levodopa or dopamine agonists
can lead to neuroleptic malignant syndrome (NMMS)… tapper off slowly
levodopa
carbidopa
levodopa- prodrug of dopamine, is the most effective agent
carbidopa: prevents peripheral metabolism of levodopa - to work 70-100 dose
PD primary tx
primary tx: replace dopamine
- give a precursor to dopamine that becomes dopamine in the brain (that’s levodopa in Sinemet)
- give dopamine agonist that act like dopamine
- give other drugs for specific symptoms (benztropine for resting tremor)
tremor-predominants disease in younger pts
can be tx w/centrally-acting anticholinergic (e.g. benztropine)
carbidopa/levodopa
Sinemet
- contra w/non-selective MOA (14 day washout)
70-100 mg of carbidopa required
- coombs test: positive d/c (hemodialysis risk)
COMT inhibitors
increase the duration of action of levodopa by inhibiting the enzyme COMT (catechol-O-methyltransferase) to prevent peripheral conversation of levodopa.
COMT should only be sued w/ levodopa
entacapone
+ carbidopa/levodopa
Comtan
Stalevo
- COMT inhibitor
Pramipexole
Mirapex
warning: somnolence (including sudden daytime sleep attacks)
impulsive disorder…
postural deformity
- dopamine agonist
Ropinirole
Requip XL
- dopamine agonist
Rotigotine
Neupro
patch!
- dopamine agonist
apomorphine
apokyn
- contra: w/ 5Ht-3 agonist (ondansetron) due to severe hypotension
- QT prolongation
severe nausea/vomiting
for emesis prevention give trimethobenzamide (Tigan)
- dopamine agonist use as a “rescue” movement drug for “off” periods
Amantadine
- blocks dopamine reuptake and also increase release of dopamine in presynaptic
- primarily used to tx dyskinesia associated w/ peak-dose of carbidopa/levodopa
warning: somnolence (including falling asleep w/out warning during activities of daily living, psychosis!
SE: hypotension, dizziness… also livedo reticularis (reddish skin mottling!)
selective MAO-B inhibitors
block the breakdown of dopamine, primarily used as adjunctive tx to carbidopa/levodopa; rasagiline has a indication for monotherapy
selegiline (capsule genetic)
- Zelapar- ODT
- Emsam- patch only indicated for depression
rasagiline (azilect)
Safinamide (Xadago)
benzatropine
Cogentin
centrally acting anticholinergic: have anticholinergic and antihistamine effects: primarily used for tremors
natural products for memory-related lol
viatmine E (2,000 IU dialy)
ginkgo
MMSE
mini-mental state exam, max 30 and less than 24 is a memory disorder
key drugs that can worsen dementia
- antiemetics (e.g. promethazine)
- antihistamine (e.g. diphenhydramine, doxylamine)
- antipsychotics (e.g. chlorpromazine, aripiprazole)
- barbiturates (e.g. phenobarbital, butalbital)
- benzodiazepines (e.g. alprazolam, clonazepam)
- centrally acting anticholinergic (e.g. benztropine)
- peripheral anticholinergics (including incontinence and IBS drugs)
- Skeletal muscle relaxants (e.g. baclofen)
- Other CNS depressants (e.g. opioids, sedative-hypnotics)
mild-moderate Alzheimer’s disease
donepezil, rivastigmine, galantamine
(acetylcholinesterase inhibitor)
moderate-severe
donepezil, rivastigmine, galantamine
(acetylcholinesterase inhibitor)
and/or memantine
donepezil
+ memantine
aricept
Namzaric
QHS to decrease nausea
if stable on 10mg donepezil, can switch to namzaric
- acetylcholinesterase inhibitor
Rivastigmine
exelon
- patch form has less nausea! does not contain metal so do not have to remove for MRI
- acetylcholinesterase inhibitor
memantine
Namenda
ER capsules and numeric can be sprinkled on apple sauce after the opened
- blocks NMDA receptor, which inhibits glutamate from binding and decreases abnormal neuron activation
key drugs that can lower seizure threshold
- bupropion
- clozapine
- theophylline
- varenicline
- carbapenems (esp. imipenem)*
- lithium*
- meperidine*
- quinolones*
- tramadol*
*High doses and renal impairment
diastat acudial dispensing
- Each package contains two rectal syringes and prefilled w/ diazepam rectal gel
syringes MUST be dialed to the right dose and locked BEFORE DISPENSING. Syringes come in 2.5, 10, and 20mg
Pharmacist instructions for locking diastat acudial
- Hold the barrel of the syringe in one hand w/ the cap facing down and some window visible. Do not remove cap
- Use the other hand to grab the cap firmly and turn to adjust the dose
- confirm the correct dose in the window, hold the locking ring at the bottom of the syringe barrel and push upward to lock both sides of the ring
- Repeat these steps w/ he second syringe in the case
once locked, the green band should say “READY”
benzo
AED mechanism of action
increase GABA
AED= antiepileptic drugs
Valproic acid
AED mechanism of action
increase GABA
phenobarbital
AED mechanism of action
enhance/potentiate GABA efects
levetiracetam
AED mechanism of action
Ca channel blocker and increase GABA
ethosuximide
AED mechanism of action
t-type Ca channel blocker
pregaba/ gaba
AED mechanism of action
Ca channel blocker
oxcarbazepine
AED mechanism of action
Na and Ca channel blocker
carbamazepine
AED mechanism of action
Na channel blocker
lamotrigine
AED mechanism of action
Na channel blocker
phenytoin/fosphenytoin
AED mechanism of action
Na channel blocker
topiramate
Na channel blocker
carbamazepine, oxcarbazepine, eslicarbazepine
AED cousins SE
hyponatremia, rash, enzyme induction
gaba and pregaba
AED cousins SE
- weight gain, peripheral edema, mild euphoria
- used primarily for neuropathic pain
phenobarbital and primidone
AED cousins SE
primidone (prodrug of phenobarbital)
- sedation, dependence/tolerance/overdose risk, enzyme induction
topiramate and zonisamide
AED cousins SE
- weight loss, metabolic acidosis
- nephrolithiasis and oligohidrosis/hyperthermia (in children)
supplement w/ AEDs
- all AEDs: Ca and Vitamin D
- women of childbearing age: folate
- Valproic acid: possibly carnitine
- lamotrigine and valproic acid: if alopecia develops, supplement w/ selenium and zinc
lamotrigine
lamictal
- SJS/TEN severe
levetiracetam
Keppra
Warning: psychiatric reactions, including psychotic symptoms, somnolence, fatigue
topiramate
topamax
- metabolic acidosis, oligohidrosis (reduced perspiration), nephrolititasis (kideny stones) , fetal harm, visual problem
- also used for migraine proplyaxis
valproic acid
divalproex
depakote, ER and sprinkle form
- hepatic failure, fetal harm
- hyperammonemia (tx w/carnitine only in adults)
also used for bipolar and migraine prophylaxis
carbamazepine
tegretol
equetro for bipolar
also used for trigeminal neuraliga
- HLA-B testing.. especially if Asian descent
contra: myelosuppression, hypersensitive to TCAs, use of MAO in past 14 days
- autoinducer
lacosamide
vimpat
- prolonged PR interval and increased risk of arrhythmias
oxcarbazepine
trileptal
- HLA-B considers for Asian pts
- not an autoinducer
phenobarbital
severe hepatic impairment contra… habit forming, respiratory depression, fetal harm….
phenytoin
Dilantin
IV rate should not exceed 50mg/min
fosphenytoin
cerebyx
fosphenytoin IV rate should not exceed 150mg PE/min
dosed in PE, phenytoin equivalents. 1mg PE= 1 mg of phenytoin
1.5mg of fosphenytoin= 1 PE
IV phenytoin admin…
- do not exceed 50mh/ min (slow infusion)
- Monitor BP, respiratory function and ECG
- requires filter
- Dilute in NS, stable for 4 hrs, do not refrigerate
NG-tube phenytoin admin
- eternal feedings (e.g. tube feeds) decrease phenytoin absorption
- Hold feeding 1-2 hrs before and after admin
IV fosphenytoin admin
- Do not exceed 150mg PE/min
- monitoring same as above
- lower risk of purple glove syndrome than phenytoin
ethosuximide
zarontin
pregabalin
lyrica
gabapentin
neurontin
vigabatrin
sabril, igadrone
- permanent vision loss >30% of pt….
primidone
mysoline
prodrug of phenobarbital
phenytoin correction
total phenytoin measured/
[(0.2xalbumin)+0.1]
AEDs enzyme inducers
carbamazepine
oxcarbamazepine
phenytoin
fosphenytoin
phenobarbital
primidone
AED enzyme inhibitors
valproic acid (increases lamotrigine dose so remember when dosing lamotrigine)
