Antiseizure Agents & Effects

7/28/2019 Antiseizure Agents & Effects

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ANTISEIZURE AGENTS & EFFECTS

Group 3

Munyadi, Muneeslaxmi

Singh, Ruby

Austin, Nissy

Khader Basha

Augustus, Joel

Jayabalan, Jerusha

Darapastham Finny1


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Topic Outlines

Introduction

Drugs Overview

Data Collection

Q & A

Conclusion

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3-7

8-11

12-15

16-21

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INTRODUCTION

What is seizure ?

Seizure results from abnormal neuronal discharge in the CNS

produced by either focal or generalized disturbances of brain

tissue.

Seizure results in abnormal phenomena of

motor (convulsion), sensory, autonomic, or psychic origin

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INTRODUCTION

Etiology & Mechanism

1. Activity of voltage-gated ion channels ( Na+, K+ & Ca++ channels)

2. Inhibitory (GABA) neurotransmission

3. Excitatory neurotransmission (Glutamate receptors)

4. Alteration of extracellular ion concentration (Potassium, calcium).

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INTRODUCTION

Types of Seizure

A. Partial Seizure B. Generalized Seizure

The discharge begins locally,

often remains localized.Produce relatively simple

symptoms w/o loss of

Consciousness.

Involve the whole brain,

including the reticular system,producing abnormal electrical

activity throughout both

hemispheres. Immediate loss

of consciousness5


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INTRODUCTION

Antiseizure Agents

They are a diverse group of pharmaceuticals used in the

treatment of epileptic seizures.

The nerve-calming qualities of some of these drugs can alsohelp quiet the burning, stabbing or shooting pain often

caused by nerve damage.

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INTRODUCTION

MOA of Antiseizure

Agents

1. Prolong inactivation of voltage-dependent Na+ channels in a use-

dependent fashion.

2. the effectiveness of inhibitory GABA transmission via the GABAA

receptor.

3. Inhibition of Ca++ currents through T-type Ca++ channels.

4. Inhibition of excitatory glutamate transmission via ionotropic

receptors. 7


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DRUGS OVERVIEW

1. Nicotine

Nicotine is taken by smoking or chewing tobacco.

Nicotine's mood-altering effects are different by report: in

particular it is both a stimulant and a relaxant. Release ofglucose from the liver and epinephrine (adrenaline) from the

adrenal medulla, it causes stimulation.

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DRUGS OVERVIEW

2. Phenobarbital

Phenobarbital is in a class of medications called barbiturates

which is used to control seizures. It is also used to prevent

withdrawal symptoms in people who are dependent onanother barbiturate medication and are going to stop taking

the medication.

It works by slowing activity in the brain.9


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DRUGS OVERVIEW

3. Phenytoin

Phenytoin is in a class of medications called anticonvulsants.

It is used to control certain type of seizures, and to treat and

prevent seizures that may begin during or after surgery tothe brain or nervous system.

It works by decreasing abnormal electrical activity in the

brain.10


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DRUGS OVERVIEW

4. Diazepam

Diazepam belongs to a group called benzodiazepines.

Diazepam is used to relieve anxiety, muscle spasms, andseizures and to control agitation caused by alcohol

withdrawal.

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DATA COLLECTION

(Group 1)

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DRUGS

EFFECTS

ONSET OF

ACTION

DURATION

OF ACTIONSEIZURE SLEEP AROUSAL

Nicotine +++ - +++ 20 secs 20 mins

Phenobarbital

+ Nicotine

++ - ++ 1 min 20 secs 1 min

Nicotine +

Phenobarbital

+ - + 15 secs 8 mins

Nicotine +

Phenytoin

++ - +++ 12 secs 12 mins

Nicotine +

Diazepam

++ - ++ 10 secs 15 mins


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DATA COLLECTION

(Group 2)

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DRUGS

EFFECTS

ONSET OF

ACTION

DURATION


Nicotine + ++ +++ 13 mins 19 mins

Phenobarbital

+ Nicotine

+ + + 15 mins 25 mins

Nicotine +

Phenobarbital

+++ ++ ++ 15 mins 17 mins

Nicotine +

Phenytoin

++ ++ ++ 15 mins 17 mins

Nicotine +

Diazepam

++ ++ ++ 7 mins 10 mins


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DATA COLLECTION

(Group 3)

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DRUGS

EFFECTS

ONSET OF

ACTION

DURATION


Nicotine + - +++ Immediate 7 mins

Phenobarbital

+ Nicotine

+ - ++ Immediate 1 min

Nicotine +

Phenobarbital

+ - ++ 30 secs 3 mins

Nicotine +

Phenytoin

+ - +++ 25 secs 2 mins

Nicotine +

Diazepam

+ - ++ 15 secs 2 mins


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DATA COLLECTION

(Group 4)

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DRUGS

EFFECTS

ONSET OF

ACTION

DURATION


Nicotine + ++ ++ 1-3 mins 7-8 mins

Phenobarbital

+ Nicotine

++ ++ + Immediate 5-7 mins

Nicotine +

Phenobarbital

- - +++ 1-2 mins 5 mins

Nicotine +

Phenytoin

+ - +++ 40 secs 2 mins

Nicotine +

Diazepam

+ - +++ 30 secs 2 mins


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Q & A

1. Drug of choice for status

epilepticus in children and

adults?

The general principles of management & the initial agents used in

the pediatric patients remain same as for adults.

Differences between adults and childrena. Etiology of status epilepticus in children differ from adults

b. Prognosis of status epilepticus is better in children than

adults.

c. Refractory of status epilepticus in children seems more

similar to that in adults16


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Q & A

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Medications class Available routes Adverse effects Advantages Disadvantages

Lorazepam

Intravenous

Rectal

Sublingual

Intramuscular

Respiratory depression

Hypotension

Decreased level of

conciousness

Prepared agent

Longer duration of action

May have least respiratory

depression of its class

Slightly longer delay in

brain uptake

Need for refrigeration

Diazepam

Intravenous

Rectal(gel form)

Intra muscular


Hypotension

Decreased level ofconciousness

Slightly faster onset of

action

Rectal examination isdone in children

Short DOA

Second line drug is

needed

Midazolam

Intravenous

intramuscular


Hypotension

Decreased level of

conciousness

Additional intramuscular

route

Short DOA

additional drug is needed

Phenytoin

intavenous Hypotension

QT prolongationPurple glove syndrome

Low cost Adverse effect profile

Fosphenytoin

Intravenous

Intramuscular

Hypotension

Cardiac arrythmias

Possibly fewer adverse

effects

Expensive

Phenobarbital

Intravenous Respiratory depression

Hypotension

Decreased level of

conciousness

Long acting Long half life


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Q & A

1. Drug of choice for status

epilepticus in children and

adults?

Initial drug of choice is : IN CHILDREN

Lorazepam iv 0.05-0.1mg/kgOrDiazepam iv 0.2-0.5mg/kg

Initial drug of choice is : IN ADULTS

Lorazepam iv 0.10.15 mg/kg OrDiazepam iv 0.3 mg/kg ,0.50.7

mg/kg recta18


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Q & A

2. Give the drugs used to

treat seizures. MOA

tabulation and specific uses

Carbamazepine

Phenobarbital

Phenytoin Primidone

Valproic acid

Lamotrigine

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Q & A

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DRUGS MOA SPECIFIC USES

Carbamazepine (Tegretol) Carbamazepine stabilizes the

inactivated Na channels. This leaves

the affected cells less excitable until

the drug dissociates.

Treating trigeminal neuralgia (a

condition that causes facial nerve

pain).

Phenobarbital (Luminal) The primary action of phenobarbital isto enhance the inhibitory actions of

(GABA) on neurons .

Prevent withdrawal symptoms inpeople who are dependent on another

barbiturate medication and are going

to stop taking the medication.

Phenytoin (Dilantin) Block Na channels, therefore limit

repetitive firing of action potentials.

Prevent seizures that may begin

during or after surgery to the brain or

nervous system.

Primidone (Mysoline) Stimulate or increase the action at the

GABA receptor.

Treatment of tremors, specifically,

essential tremor (ET), the most

common movement disorder.

Valproic Acid (Depakote) Blocks Na channels, augment the

action of GAD, , it restricts GABA-T .

Treat bipolar disorder. It is also used to

prevent migraine headaches .

Lamotrigine (Lamictal) Inhibit release of glutamate andaspartate evoked by the Na-channel Treat bipolar disorder.


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Q & A

3. MOA of nicotine

Nicotine binds to nicotinic acetylcholine receptors channels

open depolarization activate Ca channel dopamine

release epinephrine release = vasoconstriction, BP,blood sugar, rate.

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CONCLUSION

Nicotine diminishes the anticonvulsant activity of antiseizure drugs.

The combination of both nicotine and antiseizure drugs should be

carefully considered as a cause of therapeutic failure in epileptic

patients.

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Antiseizure Agents & Effects