1. ANTI-EPILEPTIC DRUG

2. SAWAN….??? EPILEPSY…????
SEIZURE…????
FIT…???

3. Objectives
• To know types of drugs used in treating
seizure/epilepsy
• To know the pharmacological actions of the
drugs
• To know the effects of drugs on the specific
functions of the system

4. Seizure
• 2nd neurologic disorder after stroke in US
• brief episodes of brain dysfunction resulting from
abnormal electrical activity of cerebral neurons
causing involuntary movement, sensations or
thoughts
• Causes: diseases, infection, head injury, heredity etc
• Epilepsy- chronic seizure (abnormal & excessive
electrical discharges of nerve cells)

5. Seizure
• A seizure occurs when the brain's nerve cells
misfire and generate a sudden, uncontrolled surge
of electrical activity in the brain
• During a seizure, each cell may fire as many as 500
times a second, much faster than the normal rate
of about 80 times a second in the brain and spinal
cord.

6. CLASSIFICATION OF
SEIZURES
Generalized seizures Partial seizures
Begin in one area of the brain & Begin in a specific area of the
rapidly spread throughout both brain & often indicate a localized
hemispheres of the brain brain lesion such as birth injury,
trauma, stroke or tumor

7. PARTIAL SEIZURES GENERALIZED
SEIZURES
- Tonic-clonic / major motor seizure
(common)
• Tonic – involves contraction of skeletal
- Simple partial seizures muscles
(consciousness is not • Clonic – rapid rhythmic & symmetric
jerking movements of the body
affected)
- Absence seizure (abrupt alterations in
- Complex partial
consciousness, lasts few seconds; etc
seizures (level of blank, staring expression
consciousness is with/without blinks of the eyelids)
decreased) - Myoclonic type ( contraction of a
muscle or group of muscles)
- Akinetic type (absence of movement )
- Mixed seizures

9. CAUSES OF SEIZURES
CHILDREN MIDDLE YEARS ELDERLY
• Birth traumas
• Head injuries • Brain tumors
• Infections
• Infections • Strokes
• Congenital
• Alcohol
abnormalities
stimulant drugs
• High fevers
• Medication side
effects

10. Antiepileptic / Antiseizure Drugs
Tonic-clonic & Myoclonic
Absence seizures Others
partial seizures seizures
Carbamazepine Ethosuximide Levetiracetam
(Zarontin) Clonazepam
(Tegrefol) (Keppra)
Valproic acid (Klonopin)
Phenytoin Gabapentin
(Dilantin) (Depakene) (Neurontin)

11. Pharmacokinetic
• Slightly soluble; good absorption; 80-100%
dose reaching circulation
• Not highly bound to protein plasma
• Cleared by hepatic mechanism; active
metabolites cleared by liver
• Medium-to long acting

12. Carbamazepine (Tegrefol)
• Strong inducing agent; therefore many drug
interactions
• It is given orally
• It is metabolized in the liver
• Contraindicated in patients with previous bone
marrow depression

13. Phenytoin (Dilantin)
• Use for patients with tonic-clonic seizures and
some partial seizures
• Acts to promote intracellular removal of
sodium during the refractory period
• Antagonism (blocking) of Na+ channels to
reduce excitability
• Antagonism of Ca++ channels
• Adverse effects: CNS (ataxia, drowsiness) &
GIT (nausea, vomiting)

14. Ethosuximide (Zarontin)
• The main drug used to treat absence seizures,
may be uses with other AEDs for treatment of
mixed seizures
• Adverse effects: nausea and anorexia. (mental
disturbances)

15. Clonazepam (Klonopin)
• Act by potentiating the actions of GABA causing
neurotransmission inhibition (primarily in the
CNS)
• Can be used to induce sleep (high dose),
anticonvulsant therapy and reduction in muscle
tone.
• Adverse effects: drowsiness, fatigue, dizziness,
muscle hypotonia, co-ordination disturbances;
also poor concentration, restlessness, confusion,
amnesia

16. Valproic acid (Depakene)
• Thought to enhance the effects of GABA in the
brain
• Used to treat manic reactions in bipolar
disorder & to prevent migraine headaches
• Extensively metabolised in the liver
• Rapidly transported across the blood brain
barrier
• Adverse effects: Nausea, vomiting, anorexia,
abdominal pain, diarrhoea & weight gain

17. Gabapentin (Neurontin)
• Incompletely absorbed in the gut
• Acts via:
– Increased synthesis and release of GABA
– Decrease degradation of GABA
– Inhibition of Ca++ channels
• Adverse effects:
– CNS effects (dizzy, drowsy, fatigue, headache, double
visions)
– Nausea and vomiting
• Contraindication: be careful with sudden withdrawal in
the elderly due to kidney effects and alterations in acid-
base balance.

19. Side Effects
• Antiepileptic drugs frequently produce CNS and
gastrointestinal side effects
• Some antiepileptic drugs infrequently cause severe
hematologic or hepatic toxicity
• Valproate and phenytoin cause birth defects