Drugs used to treat epilepsie (Anti-epileptic drugs/ AED)
Carbamazepine Mechansm of action
Carbamazepine
Pre-synantic Na+ channel blocker
Carbamazepine indications
epilepsy, trigeminal neuralgia, neuropathic pain
Side effects of carbamazepine
Dizziness Dry mouth Ataxia Fatigue Headache Diplopia Blurred vision Hyponatraemia Stevens-Johnson’s syndrome (rarely
Important PK/PD of carbamazepine
Response to the drug can be variable
Enzyme inducer of cytochrome P450; induces metabolism of itself
Interactions with other anti-convulsants
The transporter that can confer drug resistance is RALBP1
Grapefruit can significantly increase serum levels of this drug
HLA-B*1502 allele raises the risk for SJS; avoid in these patients
Patient information of carbamazepine
Avoid alcohol
Avoid grapefruit juice
Retigabine
Pre-synaptic K+ channel agonist
Mechanism of action of retigabine
Phenytoin
Pre-synaptic sodium channel blocker
Phenytoin mechanism of action
Indications for phenytoin
epilepsy (including status epilepticus
trigeminal neuralgia
Side effects of phenytoin
MORE THAN CARBAMAZEPINE Insomnia Headache Rash Constipation Vomiting Gingival hyperplasia Liver damage
Stevens-Johnson Syndrome (rare)
Leucopenia (rare)
Thrombocytopenia (rare)
Important PK/PD of phenytoin
Enzyme inducer of cytochrome P450
Can cause interactions with other anti-epileptic drugs
Narrow therapeutic index
Relationship between dose and plasma concentration is non-linear
Patient information for phenytoin
Avoid alcohol
Do not take calcium, aluminum, magnesium or iron supplements within 2 hours of ingestion
Take with food to reduce irritation
Levetiracetam
Reduces neurotransmitter release by blocking SVA2
Levetiracetam mechanism of action
Levetiracetam indication
epilepsy
Side effects of levetiracetam
Headache Fatigue Anxiety Irritability Drowsiness Constipation
Important PK/PD of levetiracetam
Patient information of levetiracetam
- Not recommended during pregnancy and breastfeeding
Pregablin and gabapentin
Blocks voltage gated Ca2+ channels to decrease neurotransmitter release
Mechanism of action of pre-gablin
- Channel inhibited by pregablin and gabapentin
Tiagabine
Gabaergic system - GABA transporter