Antiparkinsonian & Antiepileptic

Question 1

Antiepileptic drugs

Answer 1

-carbamazepine, gabapentin
-keppra
-phenytoin
topiramate
-valproic acid

Question 2

Antiepileptic drugs MOA

Answer 2

Decrease Neuronal excitability
-voltage-gated Na channel blockers = membrane stabilization
Alter Synaptic Fx
-Gabapentinoids = GABA analogues = ↓excitatory NT release
Block Neuronal Discharge
-delay NA channel reactivation
-Block T-type Ca current

Question 3

Antiepileptic SE

Answer 3

-aplastic anemia
-thrombocytopenia
-hepatotoxic
-teratogenic

Question 4

Antiepileptic drug interactions

Answer 4

-most hepatic inducers (valproic acid inhibitor)
↑ dose for lipid soluble drugs
-Thiopental, propofol, versed, opioids, NDNMBs

Question 5

Lab test alterations with Levodopa

Answer 5

-False + for ketoacidosis
-discolored urine: 1st red then black
-↑ BUN/LFT
-positive Coombs test

Question 6

CV Changes with Levodopa

Answer 6

Orthostatic HoTN
Dysrhythmias
-B adrenergic effects
- tachy/PVC
-afib
Propranolol effective tx
Transient skin flushing
Peripheral vasoconstriction
a-adrenergic effects
Hypo K
-↑ aldosterone
- ↑ arrhythmias

Question 7

Levodopa Long-Term SE

Answer 7

-CV changes
-Dyskinesias
-mobility issues
-Confusion
-Flat Affect
-Psychosis

Question 8

Levodopa shor-term SE

Answer 8

GI dysfx: N/V
HoTN

Question 9

Drugs to avoid with levodopa

Answer 9

-drugs that cross BBB
-Dopa antag
-5HT3 antag
-MAOi
-VitB6
-antipsychotic

Question 10

Anesthetic Considerations with Levodopa

Answer 10

• no change in anesthetic requirements or muscle relaxant
  -Do NOT abruptly d/c = neuroleptic malignant-like syndrome
  -Avoid dopamine antagonists (butyrophenones, phenothiazines, metoclopramide)

Question 11

Levodopa MOA

Answer 11

-5% crosses BBB to be converted to dopamine
-95% converted systemically
-Replenish dopamine stores in basal ganglia

Question 12

Gabapentin SE

Answer 12

-Somnolence
-Fatigue
-Ataxia
-Vertigo
-GI disturbances