Epilepsy is characterized by recurrent unprovoked seizures resulting from excessive neuronal cell discharges. Seizures are classified as generalized or partial. Anti-epileptic drugs work by potentiating GABA, blocking sodium or calcium ion channels, or antagonizing glutamate. Their clinical uses depend on the seizure type. Common anti-epileptic drugs include carbamazepine, phenytoin, valproic acid, ethosuximide, and clonazepam. Each drug has specific characteristics like side effects, interactions, and indications.

1. Epilepsy
Epilepsy is a chronic condition
characterized by the tendency to
recurrent unprovoked seizures. A seizure
is a symptom resulting from paroxysmal
excessive discharges from neuronal cell
population.

2. Classification of seizures
Generalized
 tonic-clonic (grand
mal)
 absence (petit mal)
 atonic seizures
 myoclonic seizures
 infantile spasm
 febrile seizures
Partial
 simple partial seizures
 complex partial
seizures
 Partial seizures
secondarily
generalized

3. Mechanism of Action
 GABA potentiation
 Na ion channel block
 Ca ion channel block
 Glutamic acid
antagonism
 Benzodiazepines,
barbiturates, gabapentin,
tiagabin, vigabatrin
 Carbamazepine,
phenytoin
 Ethosuximide, valproic
acid
 Lamortigine, felbamate,
topiramate

4. Clinical uses depend on specific
seizure type:
1) Generalized tonic-clonic (grand mal) &
partial seizures (Carbamazepine,
Phenytoin, Valproic acid)
2) Absence seizures (Ethosuximide, Valproic
acid)
3) Myoclonic seizures (Valproic acid)
4) Status epilepticus (Diazepam i/venously)

5. Characteristic features of drugs
 Carbamazepine  Used in grand mal and
partial seizures,
trigeminal neuralgia
and bipolar disorders
CNS depression,
hematotoxicity,
induces hepatic
enzymes, teratogenic

6. Characteristic features of drugs
 Phenytoin  Used in grand mal and
partial seizures
 CNS depression,
hematotoxicity,
hirsutism, gingival
hyperplasia, induces
hepatic enzymes,
teratogenic

7. Characteristic features of drugs
 Valproic acid  Broadest spectrum –
almost all seizures types,
but preferable type is
myoclonic epilepsy,
migraine prophylaxis,
bipolar disorder
 GIT distress,
hepatoxicity, inhibition
of drug metabolism,
teratogenic

8. Characteristic features of drugs
 Ethosuximide
 Clonazepam
 Only used in absence
seizures
 GIT distress, lethargy,
 Headache
Sedation & drug
dependence

9. Characteristic features of drugs
 Felbamate
 Gabapentin (also –in
chronic neuropatic
pain)
 Lamotrigine
 Aplastic anemia,
hepatotoxicity
 Sedation, leukopenia
 Sedation,
hepatotoxicity, danger
skin reaction

10. Characteristic features of drugs
 Tiagabine
 Topiramate
 Vigabatrin
 Dizziness, tremor
 Sedation, emotional
lability, tremor, weight
loss
 Sedation, confusion,
irreversible visual field
defects, weight gain

11. Parkinson disease
 Parkinson disease involves loss of
dopaminergic activity in striatum, resulting
in excessive action of acethylcholine
 Drugs must either enhance dopaminergic
activity in striatum or decrease excessive
action of acethylcholine

12. Drugs for parkinsonism
 Levodopa/carbidopa
(Nakom, Sinemet)
 Bromocriptine & Pergolid
 Selegiline
 Entacapone, Tolcapone
 Amantadine
 Levodopa is converted by
DOPA-decarboxylase to
dopamin in CNS
 These drugs activate
striatal dopamine
receptors
 It inhibit MAO-B
 Its are COMT inhibitors
 It enhances release of
dopamin in striatum

13. Drugs for parkinsonism
 Antimuscarinics  Trihexyfenidyl
 Benztropine