Epilepsy is a chronic neurological disorder characterized by recurrent seizures. It affects approximately 1% of the population globally. Seizures occur due to an imbalance between excitatory and inhibitory neurotransmitters in the brain. Epilepsy is classified based on the origin of abnormal neuronal discharges as either focal or generalized seizures. Treatment involves pharmacotherapy with anti-epileptic drugs such as sodium channel blockers, calcium channel modulators, and GABA analogues to suppress seizure activity and control symptoms.

1. EPILEPSY
BY AFIFA SETH KWAME (INTERN PHARMACIST)

2. OBJECTIVES
Introduction
Epidemiyology
Classification of seizures
Aethiology/ pathophysiology
Signs and symptoms
Investigations
Treatment

3. INTRODUCTION
Seizure: the clinical manifestation of an abnormal and excessive excitation and synchronization of
population of cortical neurons.
Epilepsy is a recurrent seizure disorder characterized by abnormal electrical discharge from the
brain often in the cerebral cortex.
Or is a chronic seizure disorder with recurrent and unprovoked seizures.
Epilepsy is a central nervous system disorder (neurological disorder) in which the nerve cell activity
in the brain is disturbed. Causing a seizure during which one experience abnormal behavior,
symptoms and sensations including loss of consciousness.

5. EPIDEMIOLOGY
• Epilepsy is one of the commonest serious neurological disorders affecting about
39million people as in 2015. it affects 1% of the population by age 20 and 3% of
the population by age 75.
• It is more common in males than in females with overall difference being small.
• Most of those with the disorder (80%) are in the developing world.
• Epilepsy begins each year in 40-70 per 100000 in developed countries and 80-140
in developing countries.
• In developing countries its onset is more common in older children than young
adults due to high rate of trauma and infectious diseases.

6. ETIOLOGY
• Congenital causes; inborn error of metabolism
• Inherited and genetic causes. Genetic disorders have the capability of
causing epilepsy.
• Acquired causes; head trauma, neurosurgery, cerebrovascular disease,
infections(meningitis, influenza, measles, mumps) endocrine disorder
(such as hypoglycemia and hypoglycemia) intracranial neoplasm.
• Withdrawal of drugs: alcohol, benzodiazepines, barbiturates, anti-
epileptics.
• Drugs that induce seizures: some antibiotics, antidiabetics, anesthetics,
antimalarial, antidepressants.

7. PATHOPHYSIOLOGY
• Neurons are interconnected in a complex network. Each individual neuron
is linked to hundreds of other neurons via synapses.
• Neurons discharge electrical current and neurotransmitters are released at
the synaptic levels and permits inter-communication.
• Neurotransmitters are of two type: inhibitory (INT) and excitatory (ENT)
neurotransmitters.
• Inhibitory neurotransmitters: GABA(Gama amino butyric acid) acts on ion
channels and increases chloride outflow and decreases chances of action
potential formation.
• Excitatory neurotransmitters: aspartate and glutamate allow sodium and
calcium influx which paves way for action potential formation.

8. CNTD.
• In this manner, information is conveyed, transmitted and process
throughout the CNS. Seizures occur due to the imbalance between
the above inhibition and excitatory.
• A normal neuron discharges repetitively at low baseline frequencies.
If neurons are damaged/injured suffers a metabolic insult, the
changes in discharge pattern develops.
• During epilepsy, regular low frequency discharges are replaced by
burst of high frequency discharges followed by periods of inactivity.

9. • In normal brain, inhibitory circuits limit synchronous discharge (GABA particularly
plays this role).
• GABA receptors blocked Rhythmic and repetitive hypersynchronous discharge of
neurons  seizures.
• Excitatory NT  Ach , Aspartate and Glutamate also involved to develop seizures.
• Intracellular recording shows burst of rapid action potential firing with reduction of
transmembrane potential.
•  inhibitory system +  excitation   genesis of seizures
• Abnormalities in ion channels (Na+, K+, Ca-) may also be involved in seizures.

11. SIGNS AND SYMPTOMS
• SIMPTOMS SIGNS
-Loss of consciousness or awareness - Postictal sleep
-Tongue biting - Postictal confusion
-Foaming at the mouth - Tods paralysis (stroke-like weakness)
-Incontinence of stool and or urine
-Muscle twitching and movement

12. CLASSIFICATION OF EPILEPSY
• There are two main groups depending on the origin of abnormal discharge:
 Focal (Partial)
Only part of the cortex is disrupted:
Simple partial seizers
Generalized:
All the cortex is disrupted

13. FOCAL PARTIAL SEIZURE
 Arise in one cerebral hemisphere
 Simple ;
-Focal with minimal spread of abnormal discharge
-Normal consciousness and awareness are maintained.

14. COMPLEX PARTIAL
 Complex partial seizures:
-local onset and then spreads
-Altered or impaired consciousness

16. GENERALIZED SEIZURES
• Involves both hemispheres +loss of consciousness.
• Clonic – rhythmic jerking of muscles
- Frothing at the mouth
- Incontinence
- This may last approx. 2mins follow by relaxation
 Tonic- muscle stiffness which last about 20secs
- Most likely to happen during sleep.
-usually involve in all or most of the brain, affecting both
Sides of the brain.
- If the person is standing when seizures starts, they may fall.

17. TONIC

18. TONIC- CLONIC SEIZURES(GRAND MAL EPILEPSY)
• At onset patient becomes rigid and falls (tonic phase)
• Follow by tonic contraction of extremities .
 The contractions become progressively longer and
Interrupted resulting in clonic jerking, cyanosis
incontinence and tongue biting may occur.
 The seizure sizes after few minutes and often follow
by period of drowsiness, confusion, headache and sleep.

19. ATONIC (AKINETIC)
• Seizures comprises sudden loss of muscle tone
causing person to collapse to the ground.
 Recovery afterwards is very quick.
 They are rare accounting for less than 1% of
epileptic seizures seen in the general population
But more common in people with severe epilepsy
Starting in infancy.

20. ABSENCE (PETIT MAL EPILEPSY)
• Brief loss of consciousness with minor muscle twitches.
• Eye blinking
• Common in children than in adults.
• Absence seizure can be controlled with
Anti-seizure medication.

22. SECONDARILY GENERALIZED
• Begins as partial (simple or complex) and progresses into grand mal seizure.

23. RISK FACTORS
• Sleep deprivation
• Missed doses of anti-epileptic drugs (AEDs) in treated patients.
• Alcohol withdrawals, recreational drug misuse.
• Physical and mental exhaustion.
• Flickering lights (includes TV, computer screens comes under generalized epilepsy
syndromes. )
• Intercurrent infections.
• Metabolic disturbances.
• Uncommon reasons like loud noise, hot baths.

24. DIAGNOSIS
• Neurological examination/ neuropsychological test: Doctors test for behavior,
motor abilities, mental function and other symptoms.
• Medical history
• Electroencephalogram (EEG): Tracks electrical signals from the brain.
• CT scan, MRI scan: used to determine abnormalities in the brain(tumours,
bleeding cysts).
• PET(Positron Emission Tomography): used to determine active areas of the brain
and determine abnormalities.
• FMRI: used to measure changes in blood flow.

25. TREATMENT
Pharmacotherapy is the basic therapeutic approach.
Goals of treatment:
 To control and reduce seizure frequency.
 To focus on minimum dosage of AEDs.
 To minimize ADRs associated with therapy.
 To ensure patient medication compliance.
 To ensure that the person lives normal life as far as possible.
 To reduce mobidity and mortality to improve quality of live.

26. GUIDELINES FOR USE OF AEDS
Traditionally, a single seizure is regarded as an indication for investigation.
Drug therapy is considered after 2 attacks (exceptions based on specific circumstances)
Start with one of first line drugs
Start with low dose: Gradually increase to effective dose or until side effects appear (“Start
low, increase slow”).
Check compliance
If first drug fails due to side effects or continued seizures, start second line drugs whilst
gradually withdrawing first (usually takes 3-4 weeks).

27. CLASSIFICATION OF ANTI EPILEPTIC DRUGS
Second Generation
Felbamate (Felbatol)
Gabapentin (Neurontin)
Lamotrigine (Lamictal)
Levetiracetam (Keppra)
Oxcarbazepine (Trileptal)
Pregabalin (Lyrica)
Tiagabine (Gabitril)
Topiramate (Topamax)
Zonisamide (Zonegran
First Generation
Carbamazepine (Tegretol)
Clonazepam (Klonopin)
Clorazepate (Tranxene)
Ethosuximide (Zarontin)
Phenobarbital
Phenytoin (Dilantin)
Primidone (Mysoline)
Valproic acid (Depakote

28. CHOICE OF ANTI EPILEPTIC DRUGS
Epilepsy type First line Second line Third line
Partial and /or
Secondary GTCS
Carbamazepine
Lamotrigine
Oxcarbazepine
Topiramate
SodiumValproate (in
children
S. Valproate
Tiagabine
Gabapentin
Clobazam
Phenytoin
Phenobarbital
Vigabatrin
Acetazolamide
Primary GTCS S. Valproate Lamotrigine
Topiramate
Carbamazepine
Phenytoin
Gabapentin
Phenobarbital
Tiagabine
Acetazolamide
Absence S. Valproate
Lamotrigine
Ethosuximide Clonazepam
Acetazolamide
Myoclonic Atonic S. Valproate Clonazepam Piracetam
Lamotrigine
Phenobarbital

29. PHARMACOLOGICAL TREATMENT

32. SODIUM CHANNEL BLOCKERS
• Main target for many drugs
• Sodium channels are responsible for the rising phase of the action potential in
excitable cells and membranes
• Examples
-Phenytoin
-Carbamazepine
-Oxcarbazepine
-Lamotrigine
-topiramate
-vaproic acid
-zonisamide

33. MODES OF ACTION
1 Suppress action potential
• Sodium channel blocker or modulator
• Potassium channel opener
2 Enhance GABA transmission
• GABA uptake inhibitor
• GABA mimetics
3 Suppression of excitatory transmission

34. PHENYTOIN
• Indicated for
All forms of seizures except absence seizures
 It is well absorbed when given orally
Highly bound to plasma proteins – displaced by
Valproate; salicylates
Induces Cyt P450 resulting in increase in its own
metabolism, but its metabolism is also increased
by alcohol
• Fosphenytoin: Prodrug for Phenytoin, used as IM, IV
injection

35. • Dose
• 150mg to 600mg daily
• Common side effects
• gums hyperplasia (gradual development, disfiguring, altered collagen met.)
• hirsutism (gradual development, androgen secretion)
• megaloblastic anaemia (in deficiency of folic acid)
• peripheral neuropathy
• Minor effect on cognition, less sedating
• abnormalities of vitamin D metabolism, leading to osteomalacia
• Phenytoin Induced Gingival Hyperplasia.

36. CARBAMAZEPINE
Indicated for
- is a major first-line AED for partial seizures and generalized tonic-clonic seizures except
absence and myoclonic seizure
-It is a tricyclic compound and initially was used primarily for primarily for the treatment of
trigeminal neuralgia; its value in the treatment of epilepsy was discovered quite by chance.
 Dose
-200mg to 1600mg a day in divided doses
- Available only orally
Serious effects
• Osteomalacea, folate deficency, peripheral neuropathy, water retention, hyponatraemia,
rash, ataxia, double vision.
-Carbamazepine is slowly but well absorbed after oral administration
It is the most favourable anti-epileptic.

37. OXCARBAZEPINE
• Oxcarbazepine – Blocks voltage-dependent sodium channels at high firing frequencies
– Also effects K+ channels
• Newer drug, prodrug metabolized to compound closely related to Carbamazepine.
• Is a recently developed analogue of CBZ. It was developed in an attempt to maintain
the benefits of CBZ while avoiding its auto-induction and drug interaction properties.
Licensed in over 50 countries, including the United States, OXC now is considered a
first-line therapy in some countries.
• Sedating but otherwise less toxic than Carbamazepine.

38. LAMOTRIGINE
• – Na+ channel inhibition (Ca channel & Excitatory Amino Acid( glu
& asp))
• Broad spectrum in epilepsy treatment
• Good response in monotherapy (may be drug of choice or often
an “alternative of choice”) ,Although chemically unrelated,
resembles phenytoin and carbamazepine in its pharmacological
effects
Dose
• Initially 25mg once daily for 14 days, then increased to 50mg for
further 14days, then increased in steps up to 100mg every 7- 14
days
• 100 to 200mg monotherapy or with valproate
• 200mg to 400mg with enzyme inducers
• Side effects: nausea, dizziness, blurred or double vision, ataxia, and

39. ZONISAMIDE
• Indicated as adjunct treatment of partial and generalized seizures but may be effective as a
monotherapy
• 100mg/day increased every 2 weeks to max of 400mg
• ZNS is absorbed quickly and completely, reaching peak levels in 2-4 hours. It has a relatively
long half-life of 60 hours
• It is chemically unrelated to any of the other AEDs
• The major mechanism of action of ZNS is reduction of neuronal repetitive firing by blocking
sodium channels and preventing neurotransmitter release. It also exerts influence on T-type
calcium channels and prevents influx of calcium. In addition, ZNS exhibits neuroprotective
effects through free radical scavenging.
• Side effects: Alopecia, anxiety, decreased appetiteweight loss, confusion impaired
concentration.vision disorder.

40. CALCIUM CHANNEL BLOCKERS
• General Ca2+ channel blockers have not proven to be effective AEDs.
• Most useful AEDs block low voltage activated channels (T-type).
• Some antiepileptic drugs (valproate, ethosuximide) reduce flow of calcium ions
through T-type 𝐶𝑎2+ channels thus reducing the pacemaker current that
underlines the thalamic rhythm in spike and waves seen in generalized partial
seizures.

41. ETHOSUXIMIDE
• Drug of choice in absence seizures (inactive in other seizures)
• T-type Ca2+ channel inhibition
• Dose
• 500mg to 1500 mg daily
Common side effects
• Gastro intestinal upset, nausea, drowsiness, headache, behavioural changes, hiccups, skin rashes
Half life 50 to 60 hours in adults
30 to 40 hours in children

42. SODIUM VALPROATE (VALPROIC ACID)
• First-line for generalized seizures, also used for partial seizures and very broad spectrum drug
(esp. in children)
• The only drug effective in both grand and petit mal
• Dose: child 1month-11yrs initially10-15mg/kg daily in 1-2divided doses(max per dose 600mg)
Adult : initially 600mg daily in 1-2 divided doses, maintenance dose 20-30mg/kg daily (max. 2.5g
per day)
• Also blocks Na+ and T-type Ca2+ channels and enhances GABAergic transmission
• Highly bound to plasma proteins;
• Available as capsule, syrup, IV
• Causes thinning and curling of hair
• CNS depressant; GI disturbances; weight gain due to increase appetite; teratogenic; (rare:
hepatotoxic)

43. GABAPENTIN, PREGABALIN
Gabapentin: Developed as a GABA analogue
• Acts specifically on P/Q-type calcium channels thereby reducing the release of various
neurotransmitters and modulators
• Dose :300mg to 2400mg daily (needs tds dose)
• Common side effects: drowsiness, dizziness, fatigue, ataxia, tremor, diplopia.
Pregabalin: The drug's exact mechanism of action is unclear, but it may reduce excitatory
neurotransmitter release by binding to the α2-δ protein subunit of voltage-gated calcium
channels.
• Effective in neuropathic pain.
• Less sedating than classic AEDs
• Dose
-75mg to 300mg daily.

44. AEDS THAT ACT PRIMARILY ON GABA
Tiagabine – GABA analogue –
• Interferes with GABA re-uptake (GAT-1) –
• Used as an adjunct for partial seizures
 Vigabatrin – elevates GABA levels by irreversibly inhibiting its main catabolic
enzyme, GABA transaminase .
• Used as an adjunct for partial seizures

45. STATUS EPILEPTICUS
• Most of epileptic seizures are terminated spontaneously
• Status epilepticus is, however, the exception and therefore, it
presents an emergency situation
• Seizure activity is uninterrupted
• the seizure is abnormally prolonged OR
• one seizure skips to another one (repeatedly) without patient becoming
conscious
• More than 30 minutes of continuous seizure activity
• Two or more sequential seizures spanning this period without full recovery
between seizures
• Medical emergency

46. BENZODIAZEPINES
• Benzodiazepine used for all forms of epilepsy, status epilepticus
Clonazepam
• Long-acting benzodiazepine that increases the presynaptic GABA inhibition and
reduces the monosynaptic and polysynaptic reflexes. Suppresses muscle contractions
by facilitating inhibitory GABA neurotransmission and other inhibitory transmitters
• Suppresses the spike-and-wave discharge in absence seizures by depressing nerve
transmission in motor cortex.
• Additional mech. of T-type calcium channel inhibition
• Absence & myoclonic seizures; status epilepticus treatment
• Dose
-4 to 8 mg a day
• Common side effects
• -Sedation, ataxia, behaviour problems, hyperactivity

47. Lorazepam and Diazepam
• Benzodiazepines used as first-line treatment for status epilepticus –
• Diazepam
• IV in status epilepticus treatment (rapid onset of action, redistribution may cause quite
rapid decrease of effectiveness); rectal form useful in a community setting.
• Lorazepam
• IV an alternative to diazepam in SE treatment, slower onset but longer duration of action

48. BARBITURATE
Phenobarbital
• Anti-seizure activity occurs primarily where GABA mediates neurotransmission.
 1st effective organic anti-seizure agent; useful in the treatment of partial seizures and
generalized tonic-clonic seizures
 Antiepileptic actions is seen in most of barbiturates, however, PB shows antiepileptic
action in lower conc.s with acceptable degree of sedation.
 Abrupt withdrawal can precipitate status epilepticus
 Dose
-90 to 600mg daily
Common side effects
-Sedation (tolerance develops), headache, hyperkinesia (old & young) slurred speech,
skin reactions, cognitive impairment

49. LEVETIRACETAM
• Experimental data indicate that this binding site is the synaptic vesicle protein SV2A, which is
thought to be involved in the regulation of vesicle exocytosis.
• This suggests that the SV2A may be the target of levetiracetam, resulting in the antiepileptic
action of the drug
• Dose
-500mg to 3000mg
• Indicated for
• Partial seizures, Generalised absences
• Common side effects
• Nausea, drowsiness, anorexia, headache, rash,
• Very rarely leucopenia

51. NON- PHARMACOLOGICAL TREATMENT
During seizures:
• Make pt as comfortable as possible
• Preferably lying down (ease to the floor if sitting)
• Cushion head
• Loosen tight clothing or neckwear
• Never move pt unless in dangerous places
• Never open pt’s mouth or force anything between teeth (2o lung
damage)

52. NON PHARMACOLOGICAL TREATMENT CTD.
When seizure stops:
• Turn pt into recovery position and ensure airway is clear.
• To offset cerebral hypoxia, give O2 at high conc; if available.
• Gentle restraints, as firm restraints will increase agitation and confusion.
• No drinks should be given after attacks and no extra AEDs should be given.
• Stay and reassure pt after attacks.

53. NON PHARMACOLOGICAL TREATMENT
• Ketogenic diet: ketogenic diet containing high contents of fat,
followed by proteins, carbohydrates were found to reduce seizures
in some children.
Side effects: constipation, slow growth because of nutritional
deficiencies, build up of uric acid in blood, kidney stones.
• Surgeries
- Medications can control seizures in most people with epilepsy, but
they don’t work for everyone.
-About 30% of people taking the drugs can`t tolerate the side effects.
In such cases brain surgery may be an option.

54. CONTD.
• Multiple Subpial Transection (MST)
- This procedure can help control seizures that began in the areas of
the brain that can`t be safely removed.
- The surgeon makes a series of shallow cuts in the brain tissue. This
cuts interrupt the flow of seizure impulse but don’t disturb normal
brain activity.
• Vagus nerve stimulation (VNS): A device implanted under the
skin sends an electronic jolt to the vagus nerve which controls
activity between brain and major internal organs. It lowers seizure
activity in some people with partial seizures.

55. DON’TS FOR EPILEPTIC PATIENTS
• Driving of a vehicle (if not certified to be seizure free)
• Swimming alone
• Working at heights
• Excessive alcohol ingestion
• Machine operation
• Cooking alone by open fire
• Non-compliance with AEDs
• Concealing the disorder

57. • Note!
• Epilepsy should not be understood as a single disorder, but rather as syndromic
with vastly divergent symptoms but all involving episodic abnormal electrical
activity in the brain

58. REFERENCES
• www.BNF.org
• www.e-epilepsy.org.uk/
• www.medicines.org.uk