Chapter 14: Neuro Flashcards
What are the 2 broad classifications of drugs used to treat neurological conditions
behavior/psychiatric drugs
drugs to treat other neuro disorders
what are the 7 common neurotransmitters
- acetylcholine
- norepinephrine
- dopamine
- GABA
- glutamate
- serotonin
- endorphin
what schedule are anorexiants
schedule IV controlled
clinical use of anorexiants
short term adjunct to weight loss program
what are neurotransmitters
chemicals that allow the transmission of nerve impulses across synapses
acetycholine functions
motor neurons: stimulate muscle, especially in GI tract
sensory neurons: plays a role in REM sleep
medications that affect acetylcholine are used for what?
Alzheimers disease (increases levels in brain)
wrinkles (blocls acetylcholine causing muscles to relax
examples of anorexiants
benzphetamine (Didrex)
diethylpropion (Tenuate)
mazindol (Mazinor)
phendimetrazine (Bontril)
phentermine (Adipex)
anorexiants mechanism of action
sympathommetic amines that stimulate the centers in the hypothalamus and limbic regions of the brain to tell the body it is satisfied
anorexiants and MAOIs
may cause life-threatening hypertensive crisis
anorexiants and alcohol
may cause depression
anorexiants and phenothiazines
may cause increased psychosis
anorexiant contraindications
substance abuse
recommended course of therapy for anorexiants
2 weeks on, 2 weeks off, use for no longer than 6 months
anorexiants patient education
dont take in evening
avoid alcohol
check pulse, BP
will need regular medical check-ups
Types of drugs used to treat seizures
hydantoins
iminostilbenes
succinimides
misc anticonvulsants
hydantoins mechanism of action
inhibit and stabalize electric discharges from neurons in the crtex of the brain
what is the first-line treatment for patients with generalized tonic-clonic and simple/partial complex seizures
hydantoins
what type of seizure are hydantoins NOT used for
absent complex seizures
examples of hydantoins
phenytoin (Dilantin) - PO
fosphenytoin (Cerebyx) - IV
effective plasma levels of hydantoins
10-20mch/mL
common side effects of hydantoins
gingivival hyperplasia, suicida ideation, phenytin0induced hepatitis
drugs that decrease effect of hydantoins
carbamazepine
chronic alcohol use
barbituates
rifampin
antacids
flu vaccine
what drugs do the flu vaccine interact with
hydantoins
aminopyrine
theophylline
warfarin
drugs that increase effect of hydantoins
alcohol, amiodarone, chloramphenicol, chlordiazepoxide, diazepam, isoniazid, methylphenidate, phenothiazines, phenylbutazone, saicylates, succinimides, sulfonamides, tolbutamide, trazadone
drugs that may increase OR decrease hydantoins
phenobarbital, valproate, valproic acid
what drugs are impaired BY hydantoins
corticosteroids, coumarin anticoagulants, digoxin, doxycycline, estrogens, furosemide, oral contraceptives, quinidine, rifampin, sulfonylureas, theophylline, and vitamin D
phenytoint and tricyclic antidepressants
tricyclics have been known to cause seizures so phenytoin dosages may need adjusted
hydantoin contraindications
hypersensitivities
bradycardia or SA block
pregnancy
phenytoin hypersensitivities
a syndrome that may develop in 3-8 weeks
(fever, skin rash, lymphadenopathies)
hydantoin patient education
may change urine color reddish-brown
use good oral hygeine
when can you consider weening someone off anticonvulsants
seizure free for 2 years with nirmal EEGs separated by at least 1 year
95% chance seizures WILL NOT reoccur if slowly weened off med
labs for hydantoins
baseline liver function, UA, blood counts and periodic pasma levels
examples of iminostilbenes
carbamazepine (Tegretol)
oxycarbazepine (Trileptal)
which medications are iminostilbenes chemically related to
tricyclic antidepressants
iminostilbenes mechanism of action
inhibit voltage gated sodium channels in thalamus
clinical uses for aminostilbenes
monotherapy or adjunct for partial complex seizures
trigeminal neuralgia
bipolar disorder
carbamazepine (Tegretol) black box warning
potential to cause blood dyscrasiaas, some of which are fatal
drugs that increase iminostilbenes
acetominophen
hydantoins
cimetidine
erythromycin
verapamil
grapefruit juice
drugs that decrease iminostilbenes
phenobarbital
phenytoin
rifampin
theophylline
herbs that reduce the seizure threshold
evening primrose, St. John’s wort, valerian, kava
iminostilbenes contraindications
hypersensitivities to tricyclic antidepressants
use with MAOIs
coadministration with nefazodone
history of blood disorders (especially bone marrow suppression)
pregnancy
plasma levels of iminostilbenes
monitor regularly
therapeutic is 4-12mcg/mL
children can develop toxicities below 12mcg/mL
clinical uses for succinimides
treatment of absent complex seizres in children and adults
succinimides mechanism of action
decrease nerve impulses and transmission in the motor cortex
why are succinimides the first choice for absent complex seizures
lacks idiosyncratic hepatotoxicity of depakote
example of succinimides
ethosuximide (Zarontin)
which drugs increase liklihood of CNS depression when administered with succinimides
tricyclic andtidepressants
phenothiazines
antihistamines
alcohol
succinimides contraindications
hypersensitivity
succinimide patient education
GI upset can be minimized by taking with milk
use backup birth control
examples of misc anticonvulsants
- zonisamide
- gabapentin
- tiagabine
- valproate
- lamotrigine
- felbamate
- clonazepam
- primidone
what is primidone mosty used for
relief of essential tremor
information on misc anticonvulsants
page 249-250
what are prescription sleep aides classified as
nonbenzodiazepine hypnotics because they act on benzo receptors in the brain
they are also called GABAergics (act on GABA receptors)
what drugs increase effect of sleep aids
benzos
alcohol
ketoconazole
erythromycin
clarithromycin
protease inhibitors
which medications ar made less effective BY sleep aides
ones that compete for CYP3A4 isoenzyme
cimetadine
rifampin, phenytoin
carbamazepine
sleep aide contraindications
hypersensitivities
pregnancy
active ingredient in OTC sleep aides
diphenhydramine and doxylamine
(older antihistamines)
some are combined with ASA or acetominophen and one of the two antihistamines
sleeps aids duration of use and class schedule
schedule IV
recommended 2 weeks (acute)
no more than 3 months (chronic)
three migraine categories
with aura (classic)
without aura (common)
complicated (associated with focal neurological deficits)
what causes migraines
high serotonin levels that drop causing expansion of brain blood vessels and throbbing pain
the throbbing vessels triggers inflammation and starts the migrane
treatment of mgraines is aimed at
preventing attacks or abort at onset
which type of headaches respond to triptan and ergotamines
migraine ONLY
not tension
medications that have been approved for migraine prophylaxis
topiramate (Topamax)
propanolol (Inderal)
timolol (Blocadren)
divalproex (Depakote)
botox
when should patients NOT be placed on beta blockers for migraine prevention
if they have history of stroke
serotonin receptor agonists (Triptans)
mechanism of action
act selectively on serotonin (5-HT10) receptors in cranial ateries, causing vasoconstriction and blockage of the release of vasoactive substance that cause sterile inflammation associated with migraine
triptans and SSRIs
can cause serotonin syndrome
examples of triptans that bind to 5-HT-1B AND -1D receptors
almotriptan (Axert)
naratriptan (Amerge)
rizatriptan (Maxalt)
zolmitriptan (Zomig)
examples of triptans that bind to 5HT-1D receptors
frovotriptan (Frova)
sumatriptan (Imitrex)
examples of triptans that bind to 5-HT-1B, -1D, and -1F receptors
electriptan (Reelpax)
onset of serotonin syndrome
minutes to hours
symptoms of serotonin syndrome
agitation or restlessness, diarrhea, fast heart beat, hallucinations, increased body temp, loss of coordination, nausea, overactive reflexes, labile BP, vomiting
which triptans decrease the effect of oral contraceptives and cimetadine
zolmitriptan
naratriptan
what medication class do all triptans interact with
MAOIs
triptan contraindications
pregnancy
complicated migraine
ischemic heart disease, cerebral vascular syndromes, uncontrolled HTN (because they constrict CA vessels)
triptans and ergotamines
no triptan can be used if ergotamine derivatives have been used in preceding 24 hours
(may increase vasospastic reactions)
triptan conscientious considerations
can be administered to children
best to administer 1st dose in clinic to gage response
triptans patient education
take at signs of impending attack, can take again after 1-2 hours if symptoms return
no more than 2 doses in a 24 hour period
ergotamines mechanism of action
stimulate vascular smooth muscle which decreases the amplitude of extracranial artery pulses and the hyperfusion of the basilar artery area
examples of ergotamines
ergotamine (Ergostat, Ergomar)
ergot with caffeine (Cafergot)
dihydroergotamine (DHE 45, Migranol)
medications that interact with ergotamines
any CYP450 drugs
ergotamines contraindications
pregnancy
uncontrolled HTN, hemiplegic or basilar migraine. peripheral or cerebral vasoconstricotrs, ischemic heart disease
severe renal impairment
complicate migraine
ergotamines patient education
grapefruit juice will increase toxicity
avoid caffeine cause it can increase absorption and effects
repeating dose will not mitigate migraine if initial dose failed
why must you start low and go slow with ergotamines
GI upset can cause patient nonadherence
which neurotransmitter is MARKEDLY reduced in parkinson’s disease
dopamine
what is key in treatment of parkinson’s symptoms
L-dopa
4 classical features of parkinson’s
tremor (pill rolling is first sign)
muscle rigidity
slowness of movement
postural disturbances
what other neurotransmitters are reduced in parkinson’s
serotonin, norepinephrine
5 drug classes used to treat parkinson’s
anticholinergics
dopamine replacement drugs (dopamine precursors)
dopamine agonists
COMT inhibitors (catechol-O-methyltransferase)
MAOB inhibitor
on-off syndrome
patient swings from being totally symptom free to presenting with a full blown case of PD symptoms
happens after more than 2 years of levodopa therapy
parkinson’s meds should be used with caution in patients with which conditions
dysrhythmias
psychosis
peptic ulcer disease
HTN
liver function impairment
anticholinergics mechanism of action
allows dopamine/acetylcholine balance in brain to return to normal by blocking the excitability of central neuron pathways of the parasympathetic nervous system
anticholinergics
clinical uses
antidyskinetic to treat drug-induced EPS
adjunctive treatment of PD
examples of anticholinergics
benxtropine (Cogentin)
trihexyphenidyl (Artane)
anticholinergic interactions
CNS depressants will have additive effect when coadministered
anticholinergic contraindications
hypersensitivities
narrow-angle glaucoma
pyloric/duodenal obstruction
prostate hypertrophy or bladder neck obstruction
anticholinergic patient education
use with cautionin hot weather or during exercise
examples of dopamine agonists
bromocriptine (Parlodel)
pramipexole (Mirapex)
ropinirole (Requip)
main purpose of dopamine agonists
correct brain’s dopamine/acetylcholine imbalance to minimize or correct dyskenesia and tremor
bromocriptine mechanism of action
stumulates production of dopamine by activating postsynaptic dopamine receptors
pergolide mechanism of action
stimulates dopamine receptors in the nigrostriatal area and acts independently of dopamine synthesis
mechanism of action for pramipexole and ropinerole
non-ergot dopamine receptor agonists
mechanism of action not well understood
what is used to treat restless leg syndrome
ropinirole
dopamine agonists and alcohol
may cause disulfiram-like reaction
the serum levels of which medications are increased by cimetadine
pramipexole and ropinirole
which medication increases the risk of hallucinations and dyskinesia if taken with dopamine agonists
levodopa
dopamine agonist contraindications
sensitivities to ergot alkaloids
dopamine precursors: levodopa
stable form of dopamine
dopamine precursors: carbidopa
decarboxylase inhibitor that helps reduce the dosage required to meet therapeutic level of levodopa
clinical use of dopamine precursors
treat idiopathic PD
symtpoms of tardive dyskinesia
uncontrollable movements of body, face, tongue, arms, hand, and head
why does treatment with dopamine precursors begin with low doses that build slowly over weeks
d/t side effects and poor tolerability
examples of dopamine precursors
levodopa (Larodopa, L-Dopa)
carbidopa-levodopa (Sinemet)
carbidopa-levodopa/entacapone (Stalevo)
early sign of dopamine precursor overdose
eyelid twitching/spasm
what medications reverse effects of levodopa decreasing their effectiveness
antipsychotics
benzodiazepines,
haloperidol
phenytoin
dopamine precursors and antihypertensives
may cause additive hypotension
what foods will reduce the effect of levodopa
foods with kava and pyridoxine
what can cause hypertensive crisis if taken with levodopa alone
cocaine and MAOIs
(combination with carbidopa can help prevent this)
dopamine precursor contraindications
hypersenitivities
narrow-angle glaucoma
undiagnosed skin lesions
safety during pregnancy and in children not established
COMT inhibitors mechanism of action
metabolizes catechol compounds (dopamine and levodopa) and converts them to inactive compounds
inhibition of peripheral COMT results in an increase in plasma level of levodopa
clinical uses of COMT inhibitors
adjunt to levodopa therapy in patients who experience a wearning off of the effects of levodopa/carbadopa
examples of COMT inhibitors
tolcapone (Tasmar)
entacapone (Comtan)
COMT inhibitors effects on mental status may be increased by
CNS depressants and hypnotics
COMT inibitors and MAOIs
concomittent use not advised as both inhibit metabolic pathways of catecholamine
COMT inhibitor contraindications
hypersensitivities
children, pregnancy, lactation safety not established
COMT inhibitors black box warning
tolcapone (Tasmar) can cause fatal liver toxicities and should be reserved for those who have not responded to other parkinson’s drugs
what must be closely monitored for the first 6 months of therapy with COMT inhibitors
liver enzymes, BP, and parkinson’s symptoms
selective MAOB inhibitor that may prevent progression of PD by serving as a neuro-protectant
selegiline (Eldepryl, Carbex)
selegiline mechanism of action
prevents the breakdown of dopamine by blocking MAOB enzyme
how does seleginine slow progression of PD
by reducing the formation of toxic fe radicals produced during the metabolism of dopamine
clinical use of seleginine
adjunct to levodopa/carbidopa if patient has failed to respond to levodopa/carbidopa alone
seleginine has serious drug reactions with
demerol (meperidine)
dextromethorphan
MAOIs
methadone
propoxyphene
tramadol
seleginine can cause serotonin syndrome when given with what
SSRIs, TCAs
seleginine contraindications
hypersensitivity
use of opiod or demerol
what if the patient taking seleginine is ingesting foods high in tyramine
increased risk for hypertensive reactions
administration instruction for patient regarding seleginine
let tablet disolve on the top of tongue and don’t eat or drinkfor 5 minutes before
dose should be taken at breakfast or breakfast and lunch (if 2 doses)
symptoms of selegine overdose
hypertensive crisis, vomiting, photosensitivity, enlarged pupils
classes of drugs used to treat Alzheimer’s
acetylcholinesterase inhibitors
NMDA receptor agonist
benefit of combining memantine with a acetylcholinesterase inhibitor
has been shown to extend time before a patient requires institutional care
acetylcholine and alzheimer’s disease
cerebral roduction of choline acetyl transerfase is reduced
this causes a decrease in acetylcholine synthesis which causes impaired cortical cholinergic function
acetylcholinesterase inhibitors mechanism of action
reversible, noncompetitive, and centrally acting
impede he breakdown of acetylcholine allowing it to accumulate in the brain
which acetylcholinesterase inhibitor has the longest lasting profile
donepezil
adverse reaction of acetylcholinesterase inhibitors are caused by
too much acetylcholine accumulation in the brain
what needs to be tested frequently in patients taking acetylcholinesterase inhibitors and why
ALT because of hepatotoxicity risk
acetylcholinesterase inhibitor interactions
other drugs metabolized by CYP450 system can increase toxicity risk
alcohol increases sedation and GI irritation
acetylcholinesterase inhibitor contraindications
hypersensitivities
caution with history of GI bleed or NSAID use
clinical use of acetylcholinesterase inhibitors
mild-moderate AD
clinical use of NMDA receptor agonist
moderate to severe AD
NMDA receptor agonist mechanism of action
regulates glutamine by attaching to NMDA receptors, protecting them from overstimulation
example of NMDA receptor agonist
memantine (Namenda)
Namenda contraindications
hypersensitivity
Namenda interactions
drugs that increase (alkalize) urine such as sodium bicarb
