This document discusses antiepileptic drugs used to treat seizures and epilepsy. It describes the types and causes of seizures and classifies them as either generalized or partial seizures. Several commonly used antiepileptic drugs are described, including their mechanisms of action, pharmacokinetics, indications, and side effects. These drugs work by enhancing GABA effects, blocking sodium channels, or inhibiting calcium channels to reduce neuronal excitability and seizures. Adverse effects can include drowsiness, nausea, weight gain, and in some cases hematologic or hepatic toxicity.

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