Module 4 (Chapter 18/21) Flashcards
CNS drug effects may differ long term versus short term because of what?
Adaptive changes that occur in response to prolonged drug exposure
beneficial responses may be delayed b/c they result from adaptive changes and not from direct effects of drugs on synaptic function; they aren’t seen until CNS has had time to modify in response to prolonged drug exposure.
what is the advantage and disadvantage of the blood brain barrier?
Advantage–it protects the brain from injury by toxic substance.
disadvantage–can be a significant obstacle for entry of therapeutic agents
What is this:
a dose increase is needed because a decreased response may occur with prolonged use.
tolerance
what is this:
this involves cravings for drug effects and occurs when the drug becomes necessary for the brain to function “normally” meaning the patient should be weaned from the drug slowly to prevent an abstinence syndrome.
physical dependence
seizures are initiated by what?
seizures are initiated by a synchronous, high-frequency discharge from a group of hypoexcitable neurons called a focus
what are the traditional seizure medications?
7 meds
think “CVEF PPP”
Carbamazepine Valproic acid Fosphenytoin Ethosuximide Phenytoin Phenobarbital Primidone
What traditional anti-seizure drug treats all types of seizures (partial, complex partial. secondary generalized, tonic clonic (primary generalized),absence, and myoclonic ?
Valproic Acid
What newer anti-seizure drug treats all types of seizures?
(simple partial, complex partial, secondary generalized, tonic-clonic, absence, and myoclonic
Lamotrigine
what are 3 groups of partial seizures?
simple partial, complex partial, and partial seizures that evolve into secondarily generalized seizures
primary generalized seizures are what type?
tonic-clonic seizures
which partial seizure does not have any LOC?
simple partial seizure
Secondarily generalized seizures are in what category of seizure type and what happens?
secondary seizures start off as simple or complex but evolve into a generalized tonic-clonic seizure
what type of seizure can a person experience a hundred times a day?
absence seizures or Petit Mal seizures
Are children (age 6 months to 5 years) who experience febrile seizures at risk for developing epilepsy later in life?
NO
what are the nondrug therapy options for treatment for treating epilepsy?
neurosurgery, Vagus nerve stimulation, and ketogenic diet
neurosurgery has the best outcomes; Vagus used most
list 3 treatment options for drug selection in epliepsy?
initial treatment should just be ONE seizure drug
2nd option: new drug if 1st is ineffective
3rd option: new drug if 2nd is ineffective or do a combination of 2 anti-seizure drugs
True or false:
No drug should be considered ineffective until it has been tested in sufficiently high dosages and for a reasonable time.
True
withdrawal of anti-seizure drugs should be done how?
anti-seizure drugs should be slowly withdrawn for over a period of 6 weeks to several months.
If a patient is taking 2 anti-seizure drugs and they are to be d/c, what method should this be done in?
If a patient is taking 2 seizure drugs, they should be withdrawn sequentially but not simultaneously
which 2 drugs are likely to increase suicidality?
Topiramate and Lamotrigine
remember generally all anti-seizure drugs can increase thoughts of SI and behavior
pts who have depression are more at risk
which 8 anti-seizure medications decreases the effectiveness of birth control?
“Can everyone love Orpah pretty please real talk”
Carbamazepine, Eslicarbazepine, Lamotrigine, Oxcarbazepine, Phenytoin, Phenobarbital, Rufinamide, and Topiramate
what meds cause maternal and fetal bleeding risk?
phenytoin, phenobarbital, carbamazepine, and primidone
b/c it decreases synthesis of vitamin K
What is the difference between traditional anti-seizure drugs and newer anti-seizure drugs?
Traditional: well established efficacy, extensive research/experience, cost less, cause troublesome side effects and extensive drug interaction owing to induction of drug metabolizing enzymes.
Newer: good but less established, less research/experience, better tolerated, little or no drug interaction, limited to induction of drug metabolizing enzymes, more expensive.
Phenytoin treats what type of seizures?
Partial (simple partial, complex partial, and secondarily generalized) and primary generalized seizures
in regards to pharmacokinetics for phenytoin, what monitoring will be needed?
Due to the liver’s limited capacity to metabolize, serum drug levels and troughs are used
in regards to dosing, what is important to know for phenytoin?
at low doses, the half life is short (8hrs) and at high doses the half life is prolonged (up to 60 hrs.)
what effect does phenytoin have on the CNS?
nystagmus, diplopia, cognitive impairment, sedation
what are 3 unique side effects of phenytoin?
Gingival hyperplasia (excessive growth of gum tissue)
morbilliform (measle-like rash) which can progress to SJS or TEN,
drug reaction with eosinophilia and systemic symptoms (DRESS)
what does DRESS stand for?
Drug reaction with eosinophilia and systemic symptoms
People of what decent should not be given phenytoin because of what? and why?
Asian decent–b/c of a genetic association with the HLA (human leukocyte antigen)
this can cause a severe reaction in association with a morbilliform rash and SJS/TEN
what cardiovascular side effects does phenytoin have?
hypotension and cardiac dysrhythmias
what anti-seizure drug can cause hirsutism and vitamin D deficiency that can lead to rickets and osteomalacia?
Phenytoin
phenytoin can decrease the effects of which 3 drugs?
oral contraceptive, warfarin, glucocorticoids
what 4 drugs increase plasma levels of phenytoin?
diazepam, isoniazid, cimetidine, acute alcohol consumption
can cause phenytoin toxicity
what drugs decrease plasma levels?
carbamazepine, phenobarbital, and alcohol
breakthrough seizures can result
what interaction does enteral tube feedings have with phenytoin?
enteral tube feeding decrease phenytoin levels
what is the blackbox warning for phenytoin?
when administering IV at rate that exceeds 50mg/min , it can cause severe hypotension and cardiac dysrhythmias–cardiac monitoring needed
what is Dilantin?
phenytoin
what is cerebyx?
Fosphenytoin
what is Fosphenytoin a prodrug for?
Phenytoin
Fosphenytoin can treat what types of seizures?
partial and primary generalized seizures
partial–simple partial, complex partial, secondarily generalized partial
tonic-clonic
what adverse effect can occur during an infusion with Fosphenytoin?
temporary paresthesias and itching (in the groin)
this will resolve after infusion is completed
what is Carbatrol, Tegretol, Epitol, and Equetro’s generic name?
Carbamazepine
what type of seizures does carbamazepine treat?
partial (simple partial/complex partial) and tonic-clonic
what is the drug of choice for partial seizures?
carbamazepine
To reduce the CNS side effects of carbamazepine what should you educate the patient to do?
take it at nighttime or at bedtime to reduce adverse CNS effects
what are 4 unique side effects of carbamazepine?
It can induced bone marrow suppression, cause fatal aplastic anemia, cause SJS/TEN/DRESS, and hyponatremia
when can DRESS occur when taking carbamazepine?
it can occur up to 2-6 weeks after initiation of treatment
what effect does carbamazepine have on ADH?
it can cause increase secretion which promotes water retention
what are the 2 black box warning for carbamazepine?
it can cause serious skin reactions (SJS/TEN/Dress) and cause fatal aplastic anemia
For Asian patients that are about to take carbamazepine, what should they have done?
they should have genetic testing for the HLA-B1502gene (HLA)
carbamazepine can cause inactivation of which 2 drugs?
oral contraceptives and warfarin
phenytoin and phenobarbital have what effect on carbamazepine?
it induces hepatic drug metabolism of carbamazepine
what effect does grapefruit juice have on carbamazepine?
it can increase peak and trough levels of carbamazepine
what drug is considered first line for all partial and generalized seizures?
valproic acid
what is the major difference that valproic acid has compared to the other traditional anti-seizure drugs?
it causes minimal sedation and cognitive impairment
what are the most common effects for valproic acid?
GI effects: n/v, indigestion
enteric formulation can help improve this SE or minimized if given with food
what are the 2 major adverse events that can occur with valproic acid that make it black box warnings?
life threatening pancreatitis and hepatic/liver failure
in what trimester is valproic acid highly teratogenic?
1st trimester
can cause atrial septal defect, cleft palate, cognitive impairment
what is the rule for children and valproic acid?
don’t use any other drugs in children younger than 2 years old
what drug interaction does valproic acid have with phenobarbital?
valproic acid decreases the rate at which phenobarbital is metabolized–dosage in phenobarbital may need to be reduced
Combining topiramate with valproic acid cause a risk for what?
Hyperammonemia
think of hepatic encephalopathy s/s
what interaction does valproic acid have with carbapenem antibiotics?
it can reduce plasma levels of valproic acid and breakthrough seizures can occur
increase dosage may be needed or avoid those abx
what is the generic name for zarontin?
ethosuximide
what is the therapeutic use for ethosuximide?
it is ONLY indicated for absence seizure and is the drug of choice
what is special about ethosuximide?
only traditional drug used for absence seizures
has a long half life
lacks significant adverse effects
what are the adverse effects of ethosuximide?
dizziness, drowsiness, lethargy but diminish with continued use
phenobarbital can treat which type of seizures?
partial (simple and complex) and tonic-clonic seizures
what is important to know about phenobarbital?
can cause physical dependence
has a long half life
can cause respiratory depression in overdose
phenobarbital can interfere with the metabolism of what vitamins?
vitamin D which can cause rickets and bone marrow suppression
vitamin K which can lead to bleeding
phenobarbital can cause what side effects?
nystagmus, ataxia if taken excessively, in OD it can respiratory depression and death.
what drug interactions does phenobarbital have ?
it decreases effectiveness with oral contraceptives and warfarin
what drug interaction does phenobarbital have with valproic acid?
valproic acid increases levels by competing with phenobarbital in which the doses would have to be reduced
what paradoxical reaction can occur in the use of phenobarbital in children and adults?
children and adults can become irritable and hyperactive
can induce confusion and cognitive deficits
what is the generic drug name for Mysoline?
primidone
what chemical structure is primidone similar to?
phenobarbital
what are the uses of primidone and how is it used to treat seizures ?
It can help treat partial (simple/complex) and primary generalized (tonic-clonic)
usually taken with another anti-seizure drug (phenytoin and carbamazepine)
what effects does primidone have?
similar to phenobarbital
can cause ataxia, sedation, dizziness
can cause paradoxical reaction in older people and children
what is the one seizure med children can’t take?
Eslicarbazepine
what are the 2 preferred anti-seizure drugs for breastfeeding mothers? b/c they are protein bound
valproic acid and phenytoin
what anti-seizure meds are on the beers list?
carbamazepine, oxcarbazepine, and phenobarbital
inappropriate for 65 years and older
Phenobarbital is a high risk medication for 56 years and older
which med of the newer anti-seizure drugs induce drug metabolizing enzymes?
Oxcarbazepine
what newer anti-seizure drugs are approved for monotherapy? 7 drugs
Eslicarbazepine, Felbamate, Lacosamide, Lamotrigine, Oxcarbazepine, topiramate, and vigabatrin
what is the generic drug name for Oxtellar and Trileptal?
Oxcarbazepine
what is Oxcarbazepine a derivative of or similar to?
Carbamazepine
is oxcarbazepine approved for monotherapy or adjunctive therapy?
its approved for both types of therapies
how old is monotherapy approved for oxcarbazepine ?
approved for children above ages 4 and older
how old is adjunctive therapy approved for oxcarbazepine?
it is approved in children above 2 years of age
what drug’s side effects does oxcarbazepine have a cross sensitivity with ?
carbamazepine, they have very similar side effects
what is the drug interaction between oxcarbazepine and phenytoin?
oxcarbazepine increases phenytoin’s drug levels while
phenytoin lowers oxcarbazepine’s drug levels
what drugs raise levels of oxcarbazepine?
phenytoin, Perampanel, and Eslicarbazepine
what drugs lowers levels of oxcarbazepine?
phenytoin, valproic acid, phenobarbital
what is the generic name for lamictal?
Lamotrigine
what is lamotrigine approved for ?
adjunctive therapy of partial seizures, tonic clonic (primary generalized) seizures, and Lennox-Gastaut syndrome in adults/children over 2 years.
approved for monotherapy of partial seizures in pts at least 16 years of age who are converting from another seizure med
also can be used in absence seizures
what newer anti-seizure drug is used for all types of seizures?
lamotrigine
what is an adverse effect for lamotrigine that can be worse if taken with valproic acid concurrently?
Stevens Johnson syndrome, TEN, Dress
what is the trade name for neurotonin?
Gabapentin
what is gabapentin approved for in relation to seizures?
adjunctive therapy of partial seizures (simple partial, complex partial, with or w/out secondary generalization)
how does food affect the absorption of gabapentin?
it does not get affected by absorption
what are the side effects of gabapentin?
usually well tolerated; common SE: somnolence, dizziness, ataxia, fatigue, nystagmus, and peripheral edema
what are the drug interactions with gabapentin?
there is a lack of significant drug interactions; gabapentin is suited well for combined use with other anti-seizure drugs.
what is the generic name from Lyrica?
pregabalin
what are the indications for pregabalin?
4 approved uses: neuropathic pain associated with diabetic neuropathy post-herpetic neuralgia, adjunctive therapy for partial seizures, and fibromyalgia
Pregabalin has the adverse effect of blurred vision, what education should the patient know?
blurred vision may develop early in therapy but resolves with continued drug use
also can cause angioedema and muscle injury
in regards to fertility what effect does pregabalin have?
pregabalin decreases sperm counts and motility, it has male mediated teratogenicity. can cause fetal abnormalities
what abuse potential does pregabalin have?
it can cause euphoria
how slowly should you discontinue pregabalin?
should be discontinued slowly over 1 week
what interactions does pregabalin have?
its not an inhibitor or inducer; have no effect on oral contraceptives
what is the brand name for keppra?
Levetiracetam
what is levetiracetam approved for ?
approved for adjunctive therapy for:
myoclonic seizures in adults/adolescents older than 12 years
partial seizures in children 4 years and older
primary generalized (tonic clonic) in children/adults 6 years and older
what are the major side effects of Keppra (levetiracetam) ?
neuropsychiatric symptoms: agitation, anxiety, depression, psychosis, and asthenia
what is the generic name for Topamax?
Topiramate
what are the approved uses for topiramate?
approved for adjunctive therapy:
in pts 2 years and older with partial seizures, generalized (tonic-clonic), and seizures associated with Lennox-gastaut syndrome
approved for monotherapy: in pts 10 years and older with partial seizures or primary generalized tonic-clonic seizures
what are some adverse effects with topiramate?
it can cause blurred vision, kidney stones, metabolic acidosis, hypohidrosis (lack of sweating)
what 2 seizure drugs decrease topiramate?
phenytoin and carbamazepine
topiramate can increase levels of topiramate
when topiramate is taken with valproic acid what is the risk?
risk for Hyperammonemia
what is Gabitril’s generic name?
Tiagabine
what is tiagabine approved for?
adjunctive therapy of partial seizures in pts at least 12 years old
what 3 traditional anti-seizure drugs decrease Tiagabine’s levels?
phenytoin, carbamazepine, and phenobarbital
what is the generic name for zonegran?
Zonisamide
what is Zonisamide approved for?
approved for only adjunctive therapy of partial seizures in Adults
what adverse effects can Zonisamide have? list 5
can cause severe psychiatric effects and trigger hypersentivitiy reactions (SJS, TEN, fulminant hepatic necrosis), kidney stones/nephrolithiasis, metabolic acidosis, and hypohidrosis
ST. John’s wart, phenytoin, phenobarbital, carbamazepine, have what effect on zonisamide?
those drugs are induces of CYP3A4 and can accelerate the metabolism of Zonisamide
Grapefruit juice, azole antifungal agents (Ketoconazole) and protease inhibitors have what effect on Zonisamide ?
it slows the metabolism of Zonisamide and prolongs intensity of its effects
What is the generic name for felbatol?
Felbamate
what is felbamate approved for?
approved for both adjunctive and monotherapy in adults with partial seizures
also approved as adjunctive therapy for children with Lennox-Gastaut syndrome
What is the drug interaction between felbamate and valproic acid?
valproic acid increases levels of felbamate
what is the drug interaction between felbamate and phenytoin or carbazmazepine?
levels of felbamate are reduced
What is the major black box warning for felbamate?
list 2
can cause aplastic anemia and liver failure
what is vimpat’s generic name?
Lacosamide
what is the therapeutic use of lacosamide?
it is indicated for add-on therapy of partial onset seizures in patient 17 years and older
also used for monotherapy
what are the adverse effects of lacosamide?
it can prolong the PR interval
what is a major caution to consider when prescribing patients lacosamide?
Lacosamide should be used in caution in patients taking other drugs that prolong PR interval
beta blockers
calcium channel blockers
what drug interaction can Lacosamide have with carbamazepine, Fosphenytoin, phenytoin, and phenobarbital?
it can decrease serum concentration of Lacosamide
what is important to know about Rufinamide?
it is approved for add-on therapy for seizures associated with Lennox-Gastaut syndrome
can reduce QT interval therefore it should not be given with digoxin
reduces BC effectivness
what is Vigabatrin (Sabril) approved for? list 2
its approved for add-on therapy of complex partial seizures in adults’
monotherapy of infantile spasm in children ages 6 months to 2 years
what is a major side effect of vigabatrin (Sabril)? and what should occur if that happens?
it can cause irreversible damage to the retina which narrows the vision field (results in tunnel vision)
if vision loss is detected, discontinue the medication.
IN patients taking vigabatrin there is an increased risk for retinal damage if this drug is taken with what other drugs? list 3 types of meds/class
hydroxychloroquine (Plaquenil), glucocorticoids, tricyclic antidepressants
what is the black box warning of Vigabatrin?
it can cause permanent loss of peripheral vision
vision should be tested at baseline, then at 4 weeks then every 3 months as therapy continues
what is important to know about Ezogabine?
its for adjunctive therapy of partial onset seizures
potential for abuse
can cause urinary retention
can lead to vision loss
long term use can cause blue, gray-blue discoloration
can cause urine to be red-orange in color–this is harmless and unrelated to urinary retention
What is the blackbox warning for Ezogabine?
it can cause retinal abnormalities
what is important to know about Eslicarbazepine (Aptiom)?
it is approved for management of partial seizures and can be used as either monotherapy or adjunctive therapy
what drugs can Eslicarbazepine reduce? list 3
it can lower the levels of statins, hormonal/contraceptives, and warfarin
what is important to know about Perampanel (Fycompa)?
it is approved for adjunctive therapy for both tonic-clonic seizures and partial seizures
who can not use Perampanel (Fycompa)?
children under 12 years of age
what is the black box warning for Perampanel (Fycompa)?
it is associated with serious psychiatric reactions (anger, aggression, hostility, violence, and even homicidal ideation)
what is important to know about Brivaracetam?
approved for management of partial onset of seizures in patients aged 4 years and older
can be used as monotherapy or adjunctive therapy
shares the same general risk as older anti-seizure meds
describe complex partial seizures
can last 45 seconds-90 seconds
impaired consciousness with a period of motionless with a fixed gaze
lip smacking and hand wringing
