AED Prescription Flashcards Preview

Nurs 5229 Clinical Pharmacotherapeutics > AED Prescription > Flashcards

Flashcards in AED Prescription Deck (38)
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1
Q

Typically NPs do not

A

prescribe AEDs for epilepsy and seizures in primary care
• Neurology initiated; primary care may monitor
• Potential use of BZDs in emergency situation
• Seizure free 0-12 months before allowed to drive*

2
Q

Some AEDs can be prescribed to treat

A

migraine headache
• Topiramate
• Valproic Acid

3
Q

Some AEDs are prescribed to treat

A
Mental Health conditions
• Carbamazepine
• Valproate
• Lamotrigine
• Topiramate
• Gabapentin
4
Q

Pharmacokinetic Factors

in the Elderly - AED

A

Absorption - little change
⬧ Distribution
• Decrease in lean body mass important for highly lipid-soluble drugs
• Fall in albumin leading to higher free fraction
⬧ Metabolism - decreased hepatic enzyme content and blood flow
⬧ Excretion - decreased renal clearance

5
Q

Pharmacokinetic Factors

in Pediatrics - AED

A
⬧ Neonate - often lower per kg doses
• Low protein binding
• Low metabolic rate
⬧ Children - higher, more frequent doses
• Faster metabolism
6
Q

Pharmacokinetics in Pregnancy - AED

A
⬧ Increased volume of distribution
⬧ Lower serum albumin
⬧ Faster metabolism
⬧ Higher dose, but probably less than predicted by total level
(measure free level)
⬧ Consider more frequent dosing
⬧ Return to pre-pregnancy conditions rapidly (within 2 weeks)
after delivery
7
Q

Be aware that drug interactions may occur when there is the:

A
  • addition of a new medication when an inducer/inhibitor is present.
  • addition of inducer/inhibitor to an existing medication regimen.
  • removal of an inducer/inhibitor from chronic medication regimen.
8
Q

AEDs and Drug Interactions

A
⬧ Although many AEDs can cause pharmacokinetic
interactions, several agents appear to be less
problematic.
⬧ AEDs that do not appear to be either inducers or
inhibitors of the CYP system include:
gabapentin
lamotrigine
pregabalin
tiagabine
levetiracetam
zonisamide
lacosamide
9
Q

• Important note about oral contraceptives (OCPs):

A

• OCP efficacy is decreased by inducers, including: phenytoin, phenobarbital,
primidone, carbamazepine, and higher doses of topiramate and oxcarbazepine
• OCPs and pregnancy significantly decrease serum levels of lamotrigine.

10
Q

Serum concentrations are useful when optimizing

A

AED therapy,

assessing adherence,or teasing out drug-drug interactions.

11
Q

Serum concentations should be used to

A

They should be used to monitor pharmacodynamic and

pharmacokinetic interactions.

12
Q

Serum concentrations should be done

A

⬧ Should be done when documenting a serum concentration when a
patient is well controlled.

13
Q

Serum concentrations are also useful when

A

Serum concentrations are also useful when documenting positive or
negative outcomes associated with AED therapy.

14
Q

Serum concentrations most often indvidual patients

A

Most often individual patients define their own “therapeutic range” for
AEDs.

15
Q

Serum concentrations for the newAED there is no clearly

A

For the new AEDs there is no clearly defined “therapeutic range”.

16
Q

Metabolic Changes of AEDs - Febrile

A
  • ↑ metabolic rate and ↓ serum concentrations

* ↑ serum proteins that can bind AEDs and ↓ free levels of AED serum concentrations

17
Q

Metabolic Changes of AEDs - Severe hepatic disease

A
  • Impairs metabolism and ↑ serum levels of AEDs
  • ↓ serum proteins and ↑ free levels of AED serum concentrations
  • Often serum levels can be harder to predict in this situation
18
Q

Metabolic Changes of AEDs - Renal

A
  • ↓ the elimination of some AEDs

* gabapentin, pregabalin, levetiracetam

19
Q

Metabolic Changes of AEDs - Chronic Renal

A
  • ↑ protein loss and ↑ free fraction of highly protein bound AEDs
  • It may be helpful to give smaller doses more frequently to ↓ adverse effects
  • phenytoin, valproic acid, tiagabine, vigabatrin
20
Q

Metabolic Changes of AEDs - Hemodialysis

A

⬧ Serum concentrations pre/post dialysis can be beneficial in this patient population
⬧ Bolus dosing of AEDs is sometimes recommended in this situation

21
Q

Sedation, fatigue -

A

All AEDs, except unusual with LTG and FBM

− More pronounced with traditional AED

22
Q

Unsteadiness, incoordination, dizziness

A

− Mainly traditional AEDs

− May be sign of toxicity with many AEDs

23
Q

Tremor

A

VALPORIC ACID

24
Q

Paresthesia

A

(topiramate, zonisamide)

25
Q

Diplopia, blurred vision, visual distortion

A

(carbamazepine, lamotrigine)

26
Q

Mental/motor slowing or impairment

A

(topiramate)

27
Q

Mood or behavioral changes

A

(levetiracetam)

28
Q

Changes in libido or sexual function

A

(carbamazepine,

phenytoin, phenobarbital)

29
Q

Mild to moderate laboratory changes

A
  • Hyponatremia: carbamazepine, oxcarbazepine
  • Increases in ALT or AST
  • Leukopenia
  • Thrombocytopenia
30
Q

Weight gain/appetite changes

A
  • valproic acid
  • gabapentin
  • pregabalin
  • vigabatrin
31
Q

Weight loss

A
  • topiramate
  • zonisamide
  • Felbamate
32
Q

Hematologic damage

A
Marrow aplasia,
agranulocytosis
Early symptoms: abnormal
bleeding, acute onset of
fever, symptoms of anemia
Laboratory monitoring
probably not helpful in early
detection
Felbamate aplastic anemia
approx. 1:5,000 treated
patients
Patient education
33
Q

Endocrine/Metabolic Effects

A
Osteomalacia, osteoporosis
(Vit D deficiency or other)
• carbamazepine
• barbiturates
• phenytoin
• oxcarbazepine
• valproate
34
Q

Teratogenesis (folate deficiency or other)

A
  • barbiturates
  • phenytoin
  • carbamazepine
  • valproate (neural tube defects)
  • topiramate (cleft lip/cleft palate
35
Q

Altered connective tissue metabolism or growth (facial

coarsening, hirsutism, gingival hyperplasia or contractures)

A
  • phenytoin

* phenobarbital

36
Q

Neurologic

A
  • Neuropathy
  • phenytoin
  • carbamazepine
  • Cerebellar degeneration
  • phenytoin
37
Q
Sexual Dysfunction (polycystic
ovaries et al.)
A
  • phenytoin
  • carbamazepine
  • phenobarbital
  • primidone
38
Q

AED Hypersensitivity Syndrome

A

⬧ Characterized by rash, systemic involvement
⬧ Arene oxide intermediates - aromatic ring
⬧ Lack of epoxide hydrolase
⬧ Cross-reactivity
• phenytoin
• carbamazepine
• Phenobarbital
• oxcarbazepine
⬧ Relative cross reactivity - lamotrigine