Pharma 4: ANTIEPILEPTIC DRUGS Flashcards
The Na channel blockers
- Phenytoin
- Carbamazepine
- Valproate?
- Iamotrigine
The Ca channel blockers
- Ethosuximide
2. Pregabalin
Enhancers of GABA-mediated synaptic inhibition
- BZDs
- Vigabatrin
- Tiagabin
Those that affect GLUTAMATE levels and NMDA receptors
- Iamotrigine
- Valproate
(Also Na channel blockers?)
PHENYTOIN
Use
PHENYTOIN
Uses:
- All partial seizures, whether simple or complex
- In tonic-clonic seizures
- Status epilepticus
PHENYTOIN
Adminstration
PHENYTOIN
Administered:
- Orally
- In case of STATUS EPILEPTICUS—>I.V
PHENYTOIN
MOA
PHENYTOIN
MOA: Na channel blocker
PHENYTOIN
Side effects
PHENYTOIN
Side effects:
- Nystagmus
- Ataxia
- Gingival hyperplasia (esp. in children)
- Fetal malformations ie. TERATOGENIC
eg. cleft palate
PHENYTOIN
May worsen which condition?
ABSENCE SEIZURE
PHENYTOIN
Drug interactions
PHENYTOIN
Drug interaction:
- SALICYLATES competitively inhibit plasma albumin binding
- INDUCE HEPATIC ENZYMES—> increase
metabolism of:
A- antiepileptics
B- anticoagulants
C- oral contraceptives
CARBAMAZEPINE
Administered
CARBAMAZEPINE
Administered: ORALLY
CARBAMAZEPINE
Precautions
CARBAMAZEPINE
Precautions:
- Start with a low dose with gradual build up to avoid dose-related toxicity
- Frequent liver tests
CARBAMAZEPINE
Uses
CARBAMAZEPINE
Uses:
- DRUG OF CHOICE in all partial seizures
- Tonic-clonic seizures
(Like phenytoin, minus the status epilepticus)
CARBAMAZEPINE
MOA
CARBAMAZEPINE
MOA:
Na channel blocker
CARBAMAZEPINE
Side effects
CARBAMAZEPINE
Side effects:
A- After chronic use:
i. Stupor
ii. Coma
iii. Resp depression
B- liver toxicity (frequent liver test)
VALPROATE
Administered
VALPROATE
Administered: ORALLY
VALPROATE
MOA
VALPROATE
MOA:
- BLOCK VOLTAGE GATED Na CHANNEL
- BLOCK NMDA RECEPTOR MEDIATED EXCITATION
- GABA POTENTIATION