SlideShare a Scribd company logo
1 of 30
Download to read offline
Antiepileptic Drugs
1
2
Objectives
• Classify antiepileptic drugs
• Describe pharmacology of antiepileptic drugs
– Mechanism of action
– Relevant pharmacokinetics
– Indications
– Adverse drug reactions
– Important drug interactions
• Explain pharmacological management of
epilepsy
MECHANISM OF ACTION OF ANTIEPILEPTIC DRUGS
Three main mechanisms –
• Enhancement of GABA action
• Inhibition of sodium channel function
• Inhibition of calcium channel function.
Other mechanisms include -
- Inhibition of glutamate release and
- Block of glutamate receptors.
5
Classification of Anticonvulsants
Action on Ion
Channels
Enhance
GABA
Transmission
Inhibit EAA
Transmissi
on
Na+:
Phenytoin,
Carbamazepine,
Lamotrigine
Topiramate
Valproic acid
Ca++:
Ethosuximide
Valproic acid
Benzodiazepines
(diazepam,
clonazepam)
Barbiturates
(phenobarbital)
Valproic acid
Gabapentin
Vigabatrin
Topiramate
Felbamate
Felbamate
Topiramate
Mechanism of action of antiepileptic
drugs
Phenytoin, Carbamazepine,
felbamate, lamotrigine, valproic acid
• Block voltage-dependent sodium
channels at high firing frequencies
Mechanism of action of antiepileptic drugs
 Barbiturates
• Prolong GABA-mediated chloride
channel openings
 Benzodiazepines
• Increase frequency of GABA-
mediated chloride channel
openings
7
Valproate
 May enhance GABA transmission in
specific circuits
 Blocks voltage-dependent sodium channels
 Blocks T-type calcium currents
Ethosuximide
• Blocks slow, threshold, “transient” (T-type) calcium
channels in thalamic neurons
8
Mechanism of action of antiepileptic drugs(AEDs)
Newer AEDs: mechanism of action
Vigabatrin: Irreversibly inhibits GABA transaminase
Tiagabine: Interferes with GABA re-uptake
Topiramate:
– Blocks voltage-dependent sodium channels at high
firing frequencies
– Increases frequency at which GABA opens Cl-
channels (different site from benzodiazepines)
– Antagonizes glutamate actions at receptor subtype
Gabapentin: May modulate amino acid transport into brain &
May interfere with GABA re-uptake
9
Phenobarbitone
• GABA-facilitatory
• GABA-mimetic
• Adverse effects
– sedative action.
– Long term administration - behavioral
abnormalities, impairment of learning and
memory, hyperactivity in children, mental
confusion in older people.
– Rashes, megaloblastic anaemia and osteo-
malacia on prolonged use.
Uses/indications
• Generalized tonic-clonic (GTC), simple partial
(SP) and complex partial (CP) seizures:
60 mg 1-3 times a day in adults; in children (3-6
mg/kg/ day).
• Status epilepticus: may be injected i.m. or i.v.
but response is slow to develop.
• not effective in absence seizures.
Phenytoin (Diphenylhydantoin)
• Most commonly used.
• Phenytoin prolongs the inactivated state of
voltage sensitive neuronal Na+ channel and
reduces the neuronal excitability.
Pharmacokinetics
• Absorption is formulation dependent
• highly bound to plasma proteins
• fosphenytoin is for IV, IM routes
• The kinetics changes from first order to zero
order over the therapeutic range(small
increments in dose produce
disproportionately high plasma
concentrations.)
• The t1/2 - 12-24 hours progressively ↑es upto
60 hr when plasma concentration rises above
10 ug/ml as metabolizing enzymes get
saturated.
Adverse effect
At therapeutic levels -
• Gum hypertrophy:
• Hirsutism:
• Hypersensitivity reactions:
• Megaloblastic anaemia:
• Osteomalacia:
• Hyper-glycaemia.
• foetal hydantoin syndrome (hypoplastic phalanges, cleft
palate, hare lip, microcephaly),due to its areneoxide
metabolite.
Adverse effect
At high plasma levels (dose related toxicity)
• CNS- Cerebellar and vestibular manifestations:
ataxia, vertigo, diplopia, nystagmus are the most
characteristic features.
Drowsiness, behavioral alterations, mental
confusion and hallucinations.
• GIT - Epigastric pain, nausea and vomiting:
minimised by taking the drug with meals.
• CVS – hypotension & arrhythmias.
Uses
• Generalized tonic-clonic, simple and comp
lex partial seizures.
• It is ineffective in absence seizures.
Dose: 100 mg BD, maximum 400 mg/day; Children 5-8
mg/kg/day,
• Status epilepticus: occasionally used by slow
i.v. injection.
• Trigeminal neuralgia - second choice drug to
carbamazepine.
Carbamazepine
• Adverse effects
– Dose related neurotoxicity—sedation, dizziness,
vertigo, diplopia and ataxia.
– Vomiting, diarrhea
– Acute intoxication - coma, convulsions and
cardiovascular collapse.
– Hypersensitivity reactions:rashes,photosensitivity
hepatitis, lupus like syndrome
– Water retention and hyponatremia in the elderly as it
enhances ADH action.
– Teratogenic
Uses
• It is the most effective drug for CPS
• First choice drug with phenytoin for GTC and
SPS .
• Trigeminal and related neuralgias - is the drug
of choice.
• Manic depressive illness and acute mania - as
an alternative to lithium
ETHOSUXIMIDE
• Inhibit T type Ca+2 current in thalamic
neurons.
• Adverse effects
– GI intolerance, tiredness, mood changes,
agitation, headache, drowsiness and inability
to concentrate
• Uses
– Only in ABSENCE SEIZURES but Use has now
declined as many consider valproic acid to be
superior to it.
VALPROIC ACID (Sodium Valproate)
Multiple mechanisms of action :
• Phenytoin like frequency dependent
prolongation of Na* channel inactivation.
• Attenuation of Ca2+ mediated 'T' current
(ethosuximide like)
• Augmentation of release of inhibitory
transmitter GABA by inhibiting its degradation
(by GABA-transaminase) & by increasing its
synthesis.
Uses
• Highly effective in absence seizure.
• Alternative /adjuvant drug for GTCS, SPS and
CPS.
• Myoclonic and atonic seizures—control is
often incomplete, but it is the drug of choice.
• Mania and bipolar illness: as alternative to
lithium.
Adverse effects
• anorexia, vomiting, loose motions, heart burn
• Drowsiness, ataxia, tremors
• Alopecia, curling of hair, increased bleeding
tendency
• Fulminant hepatitis (very rare0
• Pancreatitis
• High incidence of PCOD in young girls
• Teraotogenic
22
LAMOTRIGINE
Blocks sodium as well as high voltage
dependent calcium channels
Uses
• Broad spectrum antiepileptic.
• Refractory cases of partial seizures and GTCS
• Absence and myoclonic or akinetic epilepsy .
• Lennox-gastaut syndrome
Adverse effects
• sleepiness, dizziness, diplopia,ataxia and vomiting.
• better tolerated than carbamazepine or phenytoin.
• Rash may be a severe
GABAPENTIN
• Enhances GABA release in brain.
• does not act as agonist at GABAA receptor.
• Reduces seizure frequency in refractory partial
seizures with or without generalization.
• Effective in SPS and CPS
• Manic depressive illness and migraine
• first line drug for pain - diabetic neuropathy and
postherpetic neuralgia,
• Adverse effects - mild sedation, tiredness, dizziness
and unsteadiness.
VIGABATRIN
• Inhibitor of GABA-transaminase which degrades
GABA
• Effective in refractory epilepsy, specially partial
seizures with or without generalization.
• Adverse effects- behavioral changes, depression
and psychosis . drowsiness, amnesia, visual field
contraction, motor disturbances, agitation in
children.
TIAGABINE
• Recently developed anticonvulsant -
potentiates GABA mediated neuronal
inhibition by depressing GABA transporter
GAT-1 which removes synaptically released
GABA into neurons & glial cells.
• Uses – add on therapy of partial seizures with
or without secondary generalization.
• Adverse effects- mild sedation, nervousness,
asthenia, amnesia & abdominal pain.
27
28
29
Reference
• Lippincots illustrated pharmacology 6th edition
page 157-168
• Essentials of Medical Pharmacology 7th edition
by KD tripathi
30

More Related Content

What's hot

What's hot (20)

Anticholinesterases
AnticholinesterasesAnticholinesterases
Anticholinesterases
 
Adrenaline pharmacology
Adrenaline pharmacologyAdrenaline pharmacology
Adrenaline pharmacology
 
Antiparkinsonian drugs - drdhriti
Antiparkinsonian drugs - drdhritiAntiparkinsonian drugs - drdhriti
Antiparkinsonian drugs - drdhriti
 
Beta blockers
Beta blockersBeta blockers
Beta blockers
 
Corticosteroids
CorticosteroidsCorticosteroids
Corticosteroids
 
Corticosteroids Pharmacology - drdhriti
Corticosteroids Pharmacology - drdhritiCorticosteroids Pharmacology - drdhriti
Corticosteroids Pharmacology - drdhriti
 
Antiemetics
AntiemeticsAntiemetics
Antiemetics
 
Neuromuscular blocker
Neuromuscular blockerNeuromuscular blocker
Neuromuscular blocker
 
Antihistaminics
AntihistaminicsAntihistaminics
Antihistaminics
 
Antidepressants - Pharmacology
 Antidepressants - Pharmacology Antidepressants - Pharmacology
Antidepressants - Pharmacology
 
Ace inhibitor
Ace inhibitorAce inhibitor
Ace inhibitor
 
Anti parkinsonian drugs
Anti parkinsonian drugsAnti parkinsonian drugs
Anti parkinsonian drugs
 
Anticholinergic drugs
Anticholinergic drugsAnticholinergic drugs
Anticholinergic drugs
 
Anti-Parkinsonism Drugs / Drugs Used in the treatment of Parkinson's Disease
Anti-Parkinsonism Drugs / Drugs Used in the treatment of Parkinson's DiseaseAnti-Parkinsonism Drugs / Drugs Used in the treatment of Parkinson's Disease
Anti-Parkinsonism Drugs / Drugs Used in the treatment of Parkinson's Disease
 
Cholinergic drugs
Cholinergic drugsCholinergic drugs
Cholinergic drugs
 
Serotonin and anti serotonin drugs
Serotonin and anti serotonin drugsSerotonin and anti serotonin drugs
Serotonin and anti serotonin drugs
 
Phenytoin
PhenytoinPhenytoin
Phenytoin
 
Drugs used in bronchial asthma
Drugs used in bronchial asthmaDrugs used in bronchial asthma
Drugs used in bronchial asthma
 
Antiarrhythmic drugs bds
Antiarrhythmic drugs bdsAntiarrhythmic drugs bds
Antiarrhythmic drugs bds
 
Anticholinergic drugs
Anticholinergic drugsAnticholinergic drugs
Anticholinergic drugs
 

Viewers also liked

Pharmacology of Antiepileptic Drugs
Pharmacology of Antiepileptic DrugsPharmacology of Antiepileptic Drugs
Pharmacology of Antiepileptic Drugsshabeel pn
 
Antiepileptics
AntiepilepticsAntiepileptics
Antiepilepticsraj kumar
 
Antiseptics and disinfectants
Antiseptics  and disinfectantsAntiseptics  and disinfectants
Antiseptics and disinfectantsNaser Tadvi
 
Pharmacotherapy of epilepsy
Pharmacotherapy of epilepsyPharmacotherapy of epilepsy
Pharmacotherapy of epilepsyDr Swaroop HS
 
Antiarrhythmic drugs
Antiarrhythmic drugsAntiarrhythmic drugs
Antiarrhythmic drugsNaser Tadvi
 
Excitotoxins their role in neurodegeneration
Excitotoxins their role in neurodegenerationExcitotoxins their role in neurodegeneration
Excitotoxins their role in neurodegenerationNaser Tadvi
 
Anticoagulants naser
Anticoagulants naserAnticoagulants naser
Anticoagulants naserNaser Tadvi
 
New drug development naser
New drug development naserNew drug development naser
New drug development naserNaser Tadvi
 
Potassium channel openers
Potassium channel openers Potassium channel openers
Potassium channel openers Naser Tadvi
 
Pharmacoeconomics & drug compliance
Pharmacoeconomics & drug compliance Pharmacoeconomics & drug compliance
Pharmacoeconomics & drug compliance Naser Tadvi
 
Drug treatment of iron deficiency anaemia
Drug treatment of iron deficiency anaemiaDrug treatment of iron deficiency anaemia
Drug treatment of iron deficiency anaemiaNaser Tadvi
 
Histamine and antihistaminics
Histamine and antihistaminicsHistamine and antihistaminics
Histamine and antihistaminicsNaser Tadvi
 
Fibrinolytics & antiplatelets
Fibrinolytics & antiplateletsFibrinolytics & antiplatelets
Fibrinolytics & antiplateletsNaser Tadvi
 
Antimalarial drugs
Antimalarial drugsAntimalarial drugs
Antimalarial drugsNaser Tadvi
 
cancer chemotherapy
cancer chemotherapycancer chemotherapy
cancer chemotherapyNaser Tadvi
 
Therapeutic drug monitoring
Therapeutic drug monitoringTherapeutic drug monitoring
Therapeutic drug monitoringNaser Tadvi
 
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparations
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparationsAntiepileptic drugs : Dr Rahul Kunkulol's Power point preparations
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparationsRahul Kunkulol
 
Anti-Epileptic Drugs
Anti-Epileptic DrugsAnti-Epileptic Drugs
Anti-Epileptic DrugsAnjz Mariano
 
Newer antiepileptic drugs
Newer antiepileptic drugsNewer antiepileptic drugs
Newer antiepileptic drugsNeurologyKota
 

Viewers also liked (20)

Pharmacology of Antiepileptic Drugs
Pharmacology of Antiepileptic DrugsPharmacology of Antiepileptic Drugs
Pharmacology of Antiepileptic Drugs
 
Antiepileptics
AntiepilepticsAntiepileptics
Antiepileptics
 
Antiseptics and disinfectants
Antiseptics  and disinfectantsAntiseptics  and disinfectants
Antiseptics and disinfectants
 
Pharmacotherapy of epilepsy
Pharmacotherapy of epilepsyPharmacotherapy of epilepsy
Pharmacotherapy of epilepsy
 
Antiarrhythmic drugs
Antiarrhythmic drugsAntiarrhythmic drugs
Antiarrhythmic drugs
 
Excitotoxins their role in neurodegeneration
Excitotoxins their role in neurodegenerationExcitotoxins their role in neurodegeneration
Excitotoxins their role in neurodegeneration
 
Antipsychotics
AntipsychoticsAntipsychotics
Antipsychotics
 
Anticoagulants naser
Anticoagulants naserAnticoagulants naser
Anticoagulants naser
 
New drug development naser
New drug development naserNew drug development naser
New drug development naser
 
Potassium channel openers
Potassium channel openers Potassium channel openers
Potassium channel openers
 
Pharmacoeconomics & drug compliance
Pharmacoeconomics & drug compliance Pharmacoeconomics & drug compliance
Pharmacoeconomics & drug compliance
 
Drug treatment of iron deficiency anaemia
Drug treatment of iron deficiency anaemiaDrug treatment of iron deficiency anaemia
Drug treatment of iron deficiency anaemia
 
Histamine and antihistaminics
Histamine and antihistaminicsHistamine and antihistaminics
Histamine and antihistaminics
 
Fibrinolytics & antiplatelets
Fibrinolytics & antiplateletsFibrinolytics & antiplatelets
Fibrinolytics & antiplatelets
 
Antimalarial drugs
Antimalarial drugsAntimalarial drugs
Antimalarial drugs
 
cancer chemotherapy
cancer chemotherapycancer chemotherapy
cancer chemotherapy
 
Therapeutic drug monitoring
Therapeutic drug monitoringTherapeutic drug monitoring
Therapeutic drug monitoring
 
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparations
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparationsAntiepileptic drugs : Dr Rahul Kunkulol's Power point preparations
Antiepileptic drugs : Dr Rahul Kunkulol's Power point preparations
 
Anti-Epileptic Drugs
Anti-Epileptic DrugsAnti-Epileptic Drugs
Anti-Epileptic Drugs
 
Newer antiepileptic drugs
Newer antiepileptic drugsNewer antiepileptic drugs
Newer antiepileptic drugs
 

Similar to Antiepileptics

antiepilepticsnaser-pptx
antiepilepticsnaser-pptxantiepilepticsnaser-pptx
antiepilepticsnaser-pptxAymanshahzad4
 
Pharmacology of anti epileptic drugs
Pharmacology of anti epileptic drugsPharmacology of anti epileptic drugs
Pharmacology of anti epileptic drugsArfi12
 
Management of Epilepsy, GTCS,
 Management of Epilepsy, GTCS, Management of Epilepsy, GTCS,
Management of Epilepsy, GTCS,ankitamishra1402
 
Epilepsy and Recent Advances.pptx
Epilepsy and Recent Advances.pptxEpilepsy and Recent Advances.pptx
Epilepsy and Recent Advances.pptxKarabiAdak
 
Antiepileptics
AntiepilepticsAntiepileptics
Antiepilepticsmayur kale
 
Anti epilectics
Anti epilecticsAnti epilectics
Anti epilecticsVenuDDon
 
ANTIEPILEPTIC DRUGS 21 12 2005.ppt
ANTIEPILEPTIC DRUGS 21 12 2005.pptANTIEPILEPTIC DRUGS 21 12 2005.ppt
ANTIEPILEPTIC DRUGS 21 12 2005.pptGhost85159
 
ANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .pptANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .pptHarishGorrepati
 
ANTIEPILEPTIC_DRUGS .ppt a very useful presentation
ANTIEPILEPTIC_DRUGS .ppt a very useful presentationANTIEPILEPTIC_DRUGS .ppt a very useful presentation
ANTIEPILEPTIC_DRUGS .ppt a very useful presentationDivyaThomas45
 
ANTIEPILEPTIC_DRUGS .pptx
ANTIEPILEPTIC_DRUGS .pptxANTIEPILEPTIC_DRUGS .pptx
ANTIEPILEPTIC_DRUGS .pptxAlexisIbarra11
 
Anti epileptics-pharmacology and guidelines
Anti epileptics-pharmacology and guidelines Anti epileptics-pharmacology and guidelines
Anti epileptics-pharmacology and guidelines Navya devireddy
 
Antiepileptic drugs notes on moa , classification
Antiepileptic drugs notes on moa  , classificationAntiepileptic drugs notes on moa  , classification
Antiepileptic drugs notes on moa , classificationvijiarumugamvsvs
 

Similar to Antiepileptics (20)

antiepilepticsnaser-pptx
antiepilepticsnaser-pptxantiepilepticsnaser-pptx
antiepilepticsnaser-pptx
 
Pharmacology of anti epileptic drugs
Pharmacology of anti epileptic drugsPharmacology of anti epileptic drugs
Pharmacology of anti epileptic drugs
 
Management of Epilepsy, GTCS,
 Management of Epilepsy, GTCS, Management of Epilepsy, GTCS,
Management of Epilepsy, GTCS,
 
Anti epileptics agents pharmacology
Anti epileptics agents pharmacologyAnti epileptics agents pharmacology
Anti epileptics agents pharmacology
 
Epilepsy and Recent Advances.pptx
Epilepsy and Recent Advances.pptxEpilepsy and Recent Advances.pptx
Epilepsy and Recent Advances.pptx
 
Recent advances epilepsy
Recent advances epilepsyRecent advances epilepsy
Recent advances epilepsy
 
Antiepileptics
AntiepilepticsAntiepileptics
Antiepileptics
 
Anti epilectics
Anti epilecticsAnti epilectics
Anti epilectics
 
ANTIEPILEPTIC DRUGS 21 12 2005.ppt
ANTIEPILEPTIC DRUGS 21 12 2005.pptANTIEPILEPTIC DRUGS 21 12 2005.ppt
ANTIEPILEPTIC DRUGS 21 12 2005.ppt
 
AntiEpileptic Drugs
AntiEpileptic DrugsAntiEpileptic Drugs
AntiEpileptic Drugs
 
ANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .pptANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .ppt
 
ANTIEPILEPTIC_DRUGS .ppt a very useful presentation
ANTIEPILEPTIC_DRUGS .ppt a very useful presentationANTIEPILEPTIC_DRUGS .ppt a very useful presentation
ANTIEPILEPTIC_DRUGS .ppt a very useful presentation
 
ANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .pptANTIEPILEPTIC_DRUGS .ppt
ANTIEPILEPTIC_DRUGS .ppt
 
ANTIEPILEPTIC_DRUGS .pptx
ANTIEPILEPTIC_DRUGS .pptxANTIEPILEPTIC_DRUGS .pptx
ANTIEPILEPTIC_DRUGS .pptx
 
Anti epileptics-pharmacology and guidelines
Anti epileptics-pharmacology and guidelines Anti epileptics-pharmacology and guidelines
Anti epileptics-pharmacology and guidelines
 
Antiepileptic drugs notes on moa , classification
Antiepileptic drugs notes on moa  , classificationAntiepileptic drugs notes on moa  , classification
Antiepileptic drugs notes on moa , classification
 
Antiseizuredrugs
AntiseizuredrugsAntiseizuredrugs
Antiseizuredrugs
 
Seizure
SeizureSeizure
Seizure
 
Epilepsy
EpilepsyEpilepsy
Epilepsy
 
Epilepsy
EpilepsyEpilepsy
Epilepsy
 

More from Naser Tadvi

Evidence based medicine and tdm
Evidence based medicine and tdmEvidence based medicine and tdm
Evidence based medicine and tdmNaser Tadvi
 
Immunopharmacology
ImmunopharmacologyImmunopharmacology
ImmunopharmacologyNaser Tadvi
 
Drug therapy in pediatric and geriatric age groups
Drug therapy in pediatric and geriatric age groupsDrug therapy in pediatric and geriatric age groups
Drug therapy in pediatric and geriatric age groupsNaser Tadvi
 
Vaccines and antisera
Vaccines and antisera Vaccines and antisera
Vaccines and antisera Naser Tadvi
 
Antimalarial drugs
Antimalarial drugs Antimalarial drugs
Antimalarial drugs Naser Tadvi
 
Drugs for leprosy
Drugs for leprosyDrugs for leprosy
Drugs for leprosyNaser Tadvi
 
Pharmacotherapy of tuberculosis
Pharmacotherapy of tuberculosisPharmacotherapy of tuberculosis
Pharmacotherapy of tuberculosisNaser Tadvi
 
Drugs for treatment of Diabetes Mellitus
Drugs for treatment of Diabetes MellitusDrugs for treatment of Diabetes Mellitus
Drugs for treatment of Diabetes MellitusNaser Tadvi
 
Drugs affecting calcium balance
Drugs affecting calcium balance Drugs affecting calcium balance
Drugs affecting calcium balance Naser Tadvi
 
Parkinsonism treatment
Parkinsonism treatmentParkinsonism treatment
Parkinsonism treatmentNaser Tadvi
 
Introduction to ans
Introduction to ansIntroduction to ans
Introduction to ansNaser Tadvi
 
Histamine and antihistaminic
Histamine and antihistaminicHistamine and antihistaminic
Histamine and antihistaminicNaser Tadvi
 
Introduction to Autonomic Nervous system
Introduction to Autonomic Nervous systemIntroduction to Autonomic Nervous system
Introduction to Autonomic Nervous systemNaser Tadvi
 
Prescription pattern of drugs in pregnancy induced hypertension in a tertiar...
Prescription pattern of drugs in pregnancy induced hypertension  in a tertiar...Prescription pattern of drugs in pregnancy induced hypertension  in a tertiar...
Prescription pattern of drugs in pregnancy induced hypertension in a tertiar...Naser Tadvi
 
profile of adverse drug reactions in a rural tertiary care hospital
profile of adverse drug reactions in a rural tertiary care hospital profile of adverse drug reactions in a rural tertiary care hospital
profile of adverse drug reactions in a rural tertiary care hospital Naser Tadvi
 
New drug development
New drug developmentNew drug development
New drug developmentNaser Tadvi
 

More from Naser Tadvi (20)

Evidence based medicine and tdm
Evidence based medicine and tdmEvidence based medicine and tdm
Evidence based medicine and tdm
 
Immunopharmacology
ImmunopharmacologyImmunopharmacology
Immunopharmacology
 
Drug therapy in pediatric and geriatric age groups
Drug therapy in pediatric and geriatric age groupsDrug therapy in pediatric and geriatric age groups
Drug therapy in pediatric and geriatric age groups
 
Vaccines and antisera
Vaccines and antisera Vaccines and antisera
Vaccines and antisera
 
Antimalarial drugs
Antimalarial drugs Antimalarial drugs
Antimalarial drugs
 
Drugs for leprosy
Drugs for leprosyDrugs for leprosy
Drugs for leprosy
 
Pharmacotherapy of tuberculosis
Pharmacotherapy of tuberculosisPharmacotherapy of tuberculosis
Pharmacotherapy of tuberculosis
 
Cephalosporins
Cephalosporins Cephalosporins
Cephalosporins
 
Penicillins
PenicillinsPenicillins
Penicillins
 
Drugs for treatment of Diabetes Mellitus
Drugs for treatment of Diabetes MellitusDrugs for treatment of Diabetes Mellitus
Drugs for treatment of Diabetes Mellitus
 
Drugs affecting calcium balance
Drugs affecting calcium balance Drugs affecting calcium balance
Drugs affecting calcium balance
 
Parkinsonism treatment
Parkinsonism treatmentParkinsonism treatment
Parkinsonism treatment
 
Introduction to ans
Introduction to ansIntroduction to ans
Introduction to ans
 
Alpha blockers
Alpha blockersAlpha blockers
Alpha blockers
 
Histamine and antihistaminic
Histamine and antihistaminicHistamine and antihistaminic
Histamine and antihistaminic
 
Introduction to Autonomic Nervous system
Introduction to Autonomic Nervous systemIntroduction to Autonomic Nervous system
Introduction to Autonomic Nervous system
 
Bioassay
BioassayBioassay
Bioassay
 
Prescription pattern of drugs in pregnancy induced hypertension in a tertiar...
Prescription pattern of drugs in pregnancy induced hypertension  in a tertiar...Prescription pattern of drugs in pregnancy induced hypertension  in a tertiar...
Prescription pattern of drugs in pregnancy induced hypertension in a tertiar...
 
profile of adverse drug reactions in a rural tertiary care hospital
profile of adverse drug reactions in a rural tertiary care hospital profile of adverse drug reactions in a rural tertiary care hospital
profile of adverse drug reactions in a rural tertiary care hospital
 
New drug development
New drug developmentNew drug development
New drug development
 

Recently uploaded

CPCSEA guidelines and IAEC committee.pptx
CPCSEA guidelines and IAEC committee.pptxCPCSEA guidelines and IAEC committee.pptx
CPCSEA guidelines and IAEC committee.pptxMs. Kiran Divekar
 
SCHOOL HEALTH SERVICES.pptx made by Sapna Thakur
SCHOOL HEALTH SERVICES.pptx made by Sapna ThakurSCHOOL HEALTH SERVICES.pptx made by Sapna Thakur
SCHOOL HEALTH SERVICES.pptx made by Sapna ThakurSapna Thakur
 
23470206-Esophageal-Cancer.ppt for medical surgical nursing
23470206-Esophageal-Cancer.ppt for medical surgical nursing23470206-Esophageal-Cancer.ppt for medical surgical nursing
23470206-Esophageal-Cancer.ppt for medical surgical nursingakoeljames8543
 
The next social challenge to public health: the information environment.pptx
The next social challenge to public health:  the information environment.pptxThe next social challenge to public health:  the information environment.pptx
The next social challenge to public health: the information environment.pptxTina Purnat
 
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand UniversityCEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand UniversityHarshChauhan475104
 
Exploring the Variety of Private Blood Tests in the UK
Exploring the Variety of Private Blood Tests in the UKExploring the Variety of Private Blood Tests in the UK
Exploring the Variety of Private Blood Tests in the UKPrivate GP London
 
Introduction to Sports Injuries by- Dr. Anjali Rai
Introduction to Sports Injuries by- Dr. Anjali RaiIntroduction to Sports Injuries by- Dr. Anjali Rai
Introduction to Sports Injuries by- Dr. Anjali RaiGoogle
 
Tans femoral Amputee : Prosthetics Knee Joints.pptx
Tans femoral Amputee : Prosthetics Knee Joints.pptxTans femoral Amputee : Prosthetics Knee Joints.pptx
Tans femoral Amputee : Prosthetics Knee Joints.pptxKezaiah S
 
World-Health-Day-2024-My-Health-My-Right.pptx
World-Health-Day-2024-My-Health-My-Right.pptxWorld-Health-Day-2024-My-Health-My-Right.pptx
World-Health-Day-2024-My-Health-My-Right.pptxEx WHO/USAID
 
Ophthalmology Ultrasound Training Course
Ophthalmology Ultrasound Training CourseOphthalmology Ultrasound Training Course
Ophthalmology Ultrasound Training CourseKafrELShiekh University
 
Prince Paulraj W HERBAL DRUG TECHNO.pptx
Prince Paulraj W HERBAL DRUG TECHNO.pptxPrince Paulraj W HERBAL DRUG TECHNO.pptx
Prince Paulraj W HERBAL DRUG TECHNO.pptxprincebieber28
 
Culture and Health Disorders Social change.pptx
Culture and Health Disorders Social change.pptxCulture and Health Disorders Social change.pptx
Culture and Health Disorders Social change.pptxDr. Dheeraj Kumar
 
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and Oculomics
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and OculomicsNext Gen Ophthalmic Imaging for Neurodegenerative Diseases and Oculomics
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and OculomicsPetteriTeikariPhD
 
Role of medicinal and aromatic plants in national economy PDF.pdf
Role of medicinal and aromatic plants in national economy PDF.pdfRole of medicinal and aromatic plants in national economy PDF.pdf
Role of medicinal and aromatic plants in national economy PDF.pdfDivya Kanojiya
 
Heme synthesis for medical And Nursing studentspptx
Heme synthesis for medical And Nursing studentspptxHeme synthesis for medical And Nursing studentspptx
Heme synthesis for medical And Nursing studentspptxRajendra Dev Bhatt
 
History and Development of Pharmacovigilence.pdf
History and Development of Pharmacovigilence.pdfHistory and Development of Pharmacovigilence.pdf
History and Development of Pharmacovigilence.pdfSasikiranMarri
 
Musculoskeletal disorders: Osteoarthritis,.pptx
Musculoskeletal disorders: Osteoarthritis,.pptxMusculoskeletal disorders: Osteoarthritis,.pptx
Musculoskeletal disorders: Osteoarthritis,.pptxraviapr7
 
Hypersensitivity and its classification .pptx
Hypersensitivity and its classification .pptxHypersensitivity and its classification .pptx
Hypersensitivity and its classification .pptxAkshay Shetty
 
Presentation on Parasympathetic Nervous System
Presentation on Parasympathetic Nervous SystemPresentation on Parasympathetic Nervous System
Presentation on Parasympathetic Nervous SystemPrerana Jadhav
 
Glucagon-9.pptx- Physiology, functions, regulation
Glucagon-9.pptx- Physiology, functions, regulationGlucagon-9.pptx- Physiology, functions, regulation
Glucagon-9.pptx- Physiology, functions, regulationSai Sailesh Kumar Goothy
 

Recently uploaded (20)

CPCSEA guidelines and IAEC committee.pptx
CPCSEA guidelines and IAEC committee.pptxCPCSEA guidelines and IAEC committee.pptx
CPCSEA guidelines and IAEC committee.pptx
 
SCHOOL HEALTH SERVICES.pptx made by Sapna Thakur
SCHOOL HEALTH SERVICES.pptx made by Sapna ThakurSCHOOL HEALTH SERVICES.pptx made by Sapna Thakur
SCHOOL HEALTH SERVICES.pptx made by Sapna Thakur
 
23470206-Esophageal-Cancer.ppt for medical surgical nursing
23470206-Esophageal-Cancer.ppt for medical surgical nursing23470206-Esophageal-Cancer.ppt for medical surgical nursing
23470206-Esophageal-Cancer.ppt for medical surgical nursing
 
The next social challenge to public health: the information environment.pptx
The next social challenge to public health:  the information environment.pptxThe next social challenge to public health:  the information environment.pptx
The next social challenge to public health: the information environment.pptx
 
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand UniversityCEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
 
Exploring the Variety of Private Blood Tests in the UK
Exploring the Variety of Private Blood Tests in the UKExploring the Variety of Private Blood Tests in the UK
Exploring the Variety of Private Blood Tests in the UK
 
Introduction to Sports Injuries by- Dr. Anjali Rai
Introduction to Sports Injuries by- Dr. Anjali RaiIntroduction to Sports Injuries by- Dr. Anjali Rai
Introduction to Sports Injuries by- Dr. Anjali Rai
 
Tans femoral Amputee : Prosthetics Knee Joints.pptx
Tans femoral Amputee : Prosthetics Knee Joints.pptxTans femoral Amputee : Prosthetics Knee Joints.pptx
Tans femoral Amputee : Prosthetics Knee Joints.pptx
 
World-Health-Day-2024-My-Health-My-Right.pptx
World-Health-Day-2024-My-Health-My-Right.pptxWorld-Health-Day-2024-My-Health-My-Right.pptx
World-Health-Day-2024-My-Health-My-Right.pptx
 
Ophthalmology Ultrasound Training Course
Ophthalmology Ultrasound Training CourseOphthalmology Ultrasound Training Course
Ophthalmology Ultrasound Training Course
 
Prince Paulraj W HERBAL DRUG TECHNO.pptx
Prince Paulraj W HERBAL DRUG TECHNO.pptxPrince Paulraj W HERBAL DRUG TECHNO.pptx
Prince Paulraj W HERBAL DRUG TECHNO.pptx
 
Culture and Health Disorders Social change.pptx
Culture and Health Disorders Social change.pptxCulture and Health Disorders Social change.pptx
Culture and Health Disorders Social change.pptx
 
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and Oculomics
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and OculomicsNext Gen Ophthalmic Imaging for Neurodegenerative Diseases and Oculomics
Next Gen Ophthalmic Imaging for Neurodegenerative Diseases and Oculomics
 
Role of medicinal and aromatic plants in national economy PDF.pdf
Role of medicinal and aromatic plants in national economy PDF.pdfRole of medicinal and aromatic plants in national economy PDF.pdf
Role of medicinal and aromatic plants in national economy PDF.pdf
 
Heme synthesis for medical And Nursing studentspptx
Heme synthesis for medical And Nursing studentspptxHeme synthesis for medical And Nursing studentspptx
Heme synthesis for medical And Nursing studentspptx
 
History and Development of Pharmacovigilence.pdf
History and Development of Pharmacovigilence.pdfHistory and Development of Pharmacovigilence.pdf
History and Development of Pharmacovigilence.pdf
 
Musculoskeletal disorders: Osteoarthritis,.pptx
Musculoskeletal disorders: Osteoarthritis,.pptxMusculoskeletal disorders: Osteoarthritis,.pptx
Musculoskeletal disorders: Osteoarthritis,.pptx
 
Hypersensitivity and its classification .pptx
Hypersensitivity and its classification .pptxHypersensitivity and its classification .pptx
Hypersensitivity and its classification .pptx
 
Presentation on Parasympathetic Nervous System
Presentation on Parasympathetic Nervous SystemPresentation on Parasympathetic Nervous System
Presentation on Parasympathetic Nervous System
 
Glucagon-9.pptx- Physiology, functions, regulation
Glucagon-9.pptx- Physiology, functions, regulationGlucagon-9.pptx- Physiology, functions, regulation
Glucagon-9.pptx- Physiology, functions, regulation
 

Antiepileptics

  • 2. 2 Objectives • Classify antiepileptic drugs • Describe pharmacology of antiepileptic drugs – Mechanism of action – Relevant pharmacokinetics – Indications – Adverse drug reactions – Important drug interactions • Explain pharmacological management of epilepsy
  • 3.
  • 4. MECHANISM OF ACTION OF ANTIEPILEPTIC DRUGS Three main mechanisms – • Enhancement of GABA action • Inhibition of sodium channel function • Inhibition of calcium channel function. Other mechanisms include - - Inhibition of glutamate release and - Block of glutamate receptors.
  • 5. 5 Classification of Anticonvulsants Action on Ion Channels Enhance GABA Transmission Inhibit EAA Transmissi on Na+: Phenytoin, Carbamazepine, Lamotrigine Topiramate Valproic acid Ca++: Ethosuximide Valproic acid Benzodiazepines (diazepam, clonazepam) Barbiturates (phenobarbital) Valproic acid Gabapentin Vigabatrin Topiramate Felbamate Felbamate Topiramate
  • 6. Mechanism of action of antiepileptic drugs Phenytoin, Carbamazepine, felbamate, lamotrigine, valproic acid • Block voltage-dependent sodium channels at high firing frequencies
  • 7. Mechanism of action of antiepileptic drugs  Barbiturates • Prolong GABA-mediated chloride channel openings  Benzodiazepines • Increase frequency of GABA- mediated chloride channel openings 7
  • 8. Valproate  May enhance GABA transmission in specific circuits  Blocks voltage-dependent sodium channels  Blocks T-type calcium currents Ethosuximide • Blocks slow, threshold, “transient” (T-type) calcium channels in thalamic neurons 8 Mechanism of action of antiepileptic drugs(AEDs)
  • 9. Newer AEDs: mechanism of action Vigabatrin: Irreversibly inhibits GABA transaminase Tiagabine: Interferes with GABA re-uptake Topiramate: – Blocks voltage-dependent sodium channels at high firing frequencies – Increases frequency at which GABA opens Cl- channels (different site from benzodiazepines) – Antagonizes glutamate actions at receptor subtype Gabapentin: May modulate amino acid transport into brain & May interfere with GABA re-uptake 9
  • 10. Phenobarbitone • GABA-facilitatory • GABA-mimetic • Adverse effects – sedative action. – Long term administration - behavioral abnormalities, impairment of learning and memory, hyperactivity in children, mental confusion in older people. – Rashes, megaloblastic anaemia and osteo- malacia on prolonged use.
  • 11. Uses/indications • Generalized tonic-clonic (GTC), simple partial (SP) and complex partial (CP) seizures: 60 mg 1-3 times a day in adults; in children (3-6 mg/kg/ day). • Status epilepticus: may be injected i.m. or i.v. but response is slow to develop. • not effective in absence seizures.
  • 12. Phenytoin (Diphenylhydantoin) • Most commonly used. • Phenytoin prolongs the inactivated state of voltage sensitive neuronal Na+ channel and reduces the neuronal excitability.
  • 13. Pharmacokinetics • Absorption is formulation dependent • highly bound to plasma proteins • fosphenytoin is for IV, IM routes • The kinetics changes from first order to zero order over the therapeutic range(small increments in dose produce disproportionately high plasma concentrations.) • The t1/2 - 12-24 hours progressively ↑es upto 60 hr when plasma concentration rises above 10 ug/ml as metabolizing enzymes get saturated.
  • 14. Adverse effect At therapeutic levels - • Gum hypertrophy: • Hirsutism: • Hypersensitivity reactions: • Megaloblastic anaemia: • Osteomalacia: • Hyper-glycaemia. • foetal hydantoin syndrome (hypoplastic phalanges, cleft palate, hare lip, microcephaly),due to its areneoxide metabolite.
  • 15. Adverse effect At high plasma levels (dose related toxicity) • CNS- Cerebellar and vestibular manifestations: ataxia, vertigo, diplopia, nystagmus are the most characteristic features. Drowsiness, behavioral alterations, mental confusion and hallucinations. • GIT - Epigastric pain, nausea and vomiting: minimised by taking the drug with meals. • CVS – hypotension & arrhythmias.
  • 16. Uses • Generalized tonic-clonic, simple and comp lex partial seizures. • It is ineffective in absence seizures. Dose: 100 mg BD, maximum 400 mg/day; Children 5-8 mg/kg/day, • Status epilepticus: occasionally used by slow i.v. injection. • Trigeminal neuralgia - second choice drug to carbamazepine.
  • 17. Carbamazepine • Adverse effects – Dose related neurotoxicity—sedation, dizziness, vertigo, diplopia and ataxia. – Vomiting, diarrhea – Acute intoxication - coma, convulsions and cardiovascular collapse. – Hypersensitivity reactions:rashes,photosensitivity hepatitis, lupus like syndrome – Water retention and hyponatremia in the elderly as it enhances ADH action. – Teratogenic
  • 18. Uses • It is the most effective drug for CPS • First choice drug with phenytoin for GTC and SPS . • Trigeminal and related neuralgias - is the drug of choice. • Manic depressive illness and acute mania - as an alternative to lithium
  • 19. ETHOSUXIMIDE • Inhibit T type Ca+2 current in thalamic neurons. • Adverse effects – GI intolerance, tiredness, mood changes, agitation, headache, drowsiness and inability to concentrate • Uses – Only in ABSENCE SEIZURES but Use has now declined as many consider valproic acid to be superior to it.
  • 20. VALPROIC ACID (Sodium Valproate) Multiple mechanisms of action : • Phenytoin like frequency dependent prolongation of Na* channel inactivation. • Attenuation of Ca2+ mediated 'T' current (ethosuximide like) • Augmentation of release of inhibitory transmitter GABA by inhibiting its degradation (by GABA-transaminase) & by increasing its synthesis.
  • 21. Uses • Highly effective in absence seizure. • Alternative /adjuvant drug for GTCS, SPS and CPS. • Myoclonic and atonic seizures—control is often incomplete, but it is the drug of choice. • Mania and bipolar illness: as alternative to lithium.
  • 22. Adverse effects • anorexia, vomiting, loose motions, heart burn • Drowsiness, ataxia, tremors • Alopecia, curling of hair, increased bleeding tendency • Fulminant hepatitis (very rare0 • Pancreatitis • High incidence of PCOD in young girls • Teraotogenic 22
  • 23. LAMOTRIGINE Blocks sodium as well as high voltage dependent calcium channels Uses • Broad spectrum antiepileptic. • Refractory cases of partial seizures and GTCS • Absence and myoclonic or akinetic epilepsy . • Lennox-gastaut syndrome Adverse effects • sleepiness, dizziness, diplopia,ataxia and vomiting. • better tolerated than carbamazepine or phenytoin. • Rash may be a severe
  • 24. GABAPENTIN • Enhances GABA release in brain. • does not act as agonist at GABAA receptor. • Reduces seizure frequency in refractory partial seizures with or without generalization. • Effective in SPS and CPS • Manic depressive illness and migraine • first line drug for pain - diabetic neuropathy and postherpetic neuralgia, • Adverse effects - mild sedation, tiredness, dizziness and unsteadiness.
  • 25. VIGABATRIN • Inhibitor of GABA-transaminase which degrades GABA • Effective in refractory epilepsy, specially partial seizures with or without generalization. • Adverse effects- behavioral changes, depression and psychosis . drowsiness, amnesia, visual field contraction, motor disturbances, agitation in children.
  • 26. TIAGABINE • Recently developed anticonvulsant - potentiates GABA mediated neuronal inhibition by depressing GABA transporter GAT-1 which removes synaptically released GABA into neurons & glial cells. • Uses – add on therapy of partial seizures with or without secondary generalization. • Adverse effects- mild sedation, nervousness, asthenia, amnesia & abdominal pain.
  • 27. 27
  • 28. 28
  • 29. 29
  • 30. Reference • Lippincots illustrated pharmacology 6th edition page 157-168 • Essentials of Medical Pharmacology 7th edition by KD tripathi 30

Editor's Notes

  1. Live
  2. metabolized in liver by hydroxylation and glucuronide conjugation.
  3. Commonest , more in younger patients. coarsening of facial features, acne. Megaloblastic anaemia: phenytoin decreases folate absorption and increases its excretion. Hypersensitivity reactions: Rashes, DLE, lymphadenopathv; neutropenia is rare but requires discontinuation of therapy Osteomalacia: increase metaboism of vit. D and interferes with calcium metabolism. inhibit insulin release and cause hyper-glycaemia. Used during pregnancy—can produce foetal hydantoin syndrome (hypoplastic phalanges, cleft palate, hare lip, microcephaly),due to its areneoxide metabolite.
  4. worsening of seizures with higher doses.