Week 10 - Anticonvulsants Flashcards
This class of medications is 1st line for tonic-clonic and partial complex seizures
Hydantoins
* phenytoin
* fosphenytoin
Abrupt discontinuation of any of the anticonvulsants increases the risk for _______
seizure
What is the MOA of the hydantoin class?
affect Na+ influx into neurons = decreased propagation of nerve impulses
True or false
The hydantoins are the most sedating of all the anticonvulsants
False
They are the least sedating
The hydantoins may worsen which type of seizures?
Absence
Due to the MOA, hydantoins are contraindicated in patients with ________ disease
heart disease
* may cause bradycardia/heart block (Na+ channel affects)
What monitoring is required for the hydantoin class?
Plasma drug levels
The carbamezapine anticonvulsants are structurally related to _______
Tricyclic antidepressants
The carbamezapine class of medications is used to treat _______
Partial or tonic-clonic seizures
Epilepsy
Bipolarism
Aggressive/assaultive behavior
What is the black box warnings associated with the carbamezapine class?
- Steven-Johnson Syndrome and Toxic epidermal necrolysis (Asian population especially at risk)
- Potential for blood dyscrasias
The carbamezapine class carries a risk of decreased ________ function
thyroid
What are the monitoring considerations with the carbamezapine class?
- CBC
- Liver function tests
- TSH levels
Because of their structural relation to another class of medications, it is important that the Carbamezapines are not administered within 14 days of _________
MAOI’s
Carbamazapine MOA
Affects Na+ channels and nerve impulse propagation
Many of the anticonvulsants share a common ADR of ___________
increased suicidal thoughts
Lamotrigine is used as __________ therapy for patients with partial or generalized seizures
adjunct
Lamotrigine carries a black box warning of?
Which medication given in conjunction increases this risk?
Steven-Johnson syndrome, Toxic epidermal necrolysis
Valproate
This possible ADR of lamotrigine necessitates monitoring of CBC
Blood dyscrasias
Anticonvulsant drugs that affect GABA include:
- Gabapentin
- Topiramate
True or false
Plasma drug level monitoring is required for gabapentin and topiramate
False
Behavior problems such as hostility/aggression, “thought disorder”, and worsening school performance has been observed in patients aged 3-12 taking ___________
Gabapentin
What possible ADR of topiramate requires labratory monitoring?
Decreased serum bicarbonate, altered electrolytes
Patients taking topiramate who have eye pain or blurred vision should _________
contact their provider immediately
* drug reaction causing acute myopia and angle closure glaucoma
Ethosuximide is a(n) ___________ with an indication of _____________
anticonvulsant, childhood and adult absence seizures
With careful monitoring of plasma drug levels, ethosuximide may be safe for use during ___________
Pregnancy
The most common ADR associated with ethosuximide is ___________ and may be relieved by ___________
GI upset, taking the medication with food or milk
Ethosuximide may decrease the effectiveness of ___________
oral contraceptives
Leviteracetam is used for _________
adjunct therapy in partial or generalized seizures
The most common ADR’s associated with leviteracetam include:
- Somnolence
- dizziness
What is a common severe side effect of phenytoin (not CNS related)
Phenytoin-induced hepatitis is a common hypersensitivity reaction
What black-box warning does phenytoin carry?
Rapid IV administration may cause severe cardiovascular events such as…
Bradycardia
SA block
2nd, 3rd degree block
Stokes-Adams
Phenytoin is a pregnancy category…
D
May cause malformations and infants exposed may experience lower vitamin K dependent clotting factors
What labs should be monitored with administration of phenytoin?
CBC
Liver labs
Urinalysis
Thyroid labs (may alter thyroid hormone demand)
What benign effect may happen to patients when on phenytoin?
May discolor urine a reddish color, not cause for alarm
Regarding lab values with carbamazepine, what may occur after months of treatment despite good compliance?
Initial concentrations within the therapeutic range may fall.
Patients taking gabapentin may experience weight __________ ?
Gain
Patients taking gabapentin may experience increased risk of?
Suicidal ideation
Patients taking lamotrigine may experience weight ________ ?
Loss
When combined with phentermine, topiramate can be used to treat
Anorexia
When used alone, topiramate causes appetite ____________ ?
Suppression
Use cautiously in patients with eating disorders due to the risk of developing low serum bicarb
Topiramate may cause ___________ if coadministered with carbonic anhydrase inhibitors (ex. acetazolamide)?
Renal calculi
What is the MOA of levetiracetam?
Inhibits burst firing without affecting normal excitability, prevents spread of seizure.
Lab monitoring needed for patients started on levetiracetam?
Trick question: None
Though you may see a transient decrease in WBC
Unique to levetiracetam is that it is approved for children ___________ month(s) or older.
One
The two most common adverse reactions to the succinimide class are?
GI distress and CNS depression
Relieve by taking meds with food and milk
What is the most common Hydantoin used?
Phenytoin
Gabapentin and topiramate are also used for?
Neuropathic pain
Migraines
