Chapter 16:Anticonvulsants DH206: Pharmacology Lisa Mayo, RDH, BSDH Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved

Chapter 16:Anticonvulsants

DH206: PharmacologyLisa Mayo, RDH, BSDH

Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.


BOARD DRUGS

Drugs most commonly used for both Gen & Partial Seizures1) Barbiurates (Phenobarbital)2) Phenytoin(Dilantin)3) Carbamazepine (Tegretol)4) Valproic acid (Depakene)5) Primidone (Mysoline)6) Levetiracetam (Keppra)7) Topiramate (Topomax)8) Zonisamide (Zonegram)

Drugs most commonly use for Partial Seizures1) Felbamate (Felbatol)2) Gabapentin (Neurontin)3) Tiagabine (Gabitril)4) Lamotrigine (Lamictal)


BOARD DRUGS

Drugs most commonly used for Absence Seizures (petit mal)1) Ethosuximide (Zarontin)2) Trimethadione (Tridione)3) Benzodiazepines: Diazepam(Valium),

Clonazepam(Klonopin), Lorazepam(Ativan) Drugs most commonly use for Status Epilepticus

1) Lorazepam(Ativan)2) Diazepam(Valium)3) Phenytoin (Dilantin)


BOARD DRUGS

Drugs most commonly used for Epileptic Seizures Absence Seizures

1) Ethosuximide (Zarotin)2) Valproic acid (Depakene)3) Lamotigine (Lamictal)

Gen Tonic-Clonic Seizures1) Phenytoin(Dilantin)2) Valproic acid (Depakene)3) Carbamazepine (Tegretol)4) Lamotigine (Lamictal) & Topiramate(Topomax) used on kids a lot (newer

drugs) Partial Seizures

1) Phenytoin(Dilantin)2) Valproic acid (Depakene)3) Carbamazepine (Tegretol)4) Lamotigine (Lamictal) & Topiramate(Topomax)


1. Seizure Types2. Epilepsy3. First-generation drug4. Second-generation drugs

Outline


Seizure Types


Seizure Types for Review

Generalized Seizures Partial Seizures

Brain Affects both hemispheres Affects 1 hemisphere

Types Absence (last <20sec)Tonic-Clonic (last 1-2min)

SimpleComplex

Consciousness Loses consciousness Does NOT lose consciousness


Epilepsy


Epilepsy

Epilepsy Common CNS disorder: 1:200 people Repeated reoccurrence of seizures Multiple etiologies


Anti-Epileptic Drug Therapy

Treatment or control of seizures depends on types of seizures the patient experiences Drugs for tonic-clonic not always effective for absence

Adverse Side Effects1) Teratogenic2) P-450 enzyme inducers3) GI

Drugs used for seizures also are used in tx of:1) Anxiety disorders2) Bipolar3) Migraine4) Neuropathic pain


First-Generation Drugs

FIRST GENERATION

DRUGS

SEZIURES USED TO TX

ACTION

Phenobarbital(Luminal) All except Absence Enhance GABA

Phenytoin(Dilantin) All except Absence Block Na channels

Carbamazepine(Tegretol)

All seizures Block Na channels

Oxcarbazepine(Trileptal)

All seizures Block Na channels

Valproic Acid(Depakene)

All seizures Block Na channelsEnhance GABA

Ethosuximide(Zarotin) Absence (generalized) Block Ca channels

Clonazepam(Klonopin) Myoclonic in kids Benzo: Enhance GABA

Lorazepam(Ativan) Status epilepticus Benzo: Enhance GABA

ALERTKNOW THIS FOR TESTS & BOARDS

INSTEAD P.197


Phenobarbital(Luminal) 1st anti-epileptic drug developed Use declining with newer drugs on the market GABA

Phenytoin(Dilantin) 1st line drug for all seizures EXCEPT absence Widely used 1st non-sedating drug Narrow TI Adverse reactions: gingival enlargement, tetratogenic,

vitamin deficiency (D & Folate)

First Generation Drugs


Carbamazepine(Tegretol) Also used for bipolar, trigeminal neuralgia Adverse effects: severe blood disorders which can lead

to gingival bleeding & agranulocytosis Blood lab tests needed for dental tx! Metabolized by P450 enzyme system – drug

interactions

Oxcarbazepine(Trileptal) Similar to Tegretol with less side effects



Valproic Acid(Depakene) Many adverse effects

Inhibit platelet aggregation: increase bleeding times

3 BLACK BOX WARNINGS1)Severe, fatal hepatoxic rxns <2yrs2)Tetratogenic: Pregnancy category D

(neural tube defects)3)Life-threatening pancreatitis




Ethosuximide (Zarontin) Drug of choice for absence seizures Adverse effects

Leukopenia (↓ WBC) Gingival enlargement Hiccups


Second-Generation Drugs Newer drugs Less side effects because more specific sites of action

SECOND GENERATION DRUGS

Levetiracetam(Keppra)

Tiagabine(Gabitril)

Lamotrigine(Lamictal)

Gabapentin(Neurotin)

Pregabalin(Lyrica)

Felbamate(Felbatol)

Topiramate(Topamax)

Zonisamide(Zonegran)


Second-Generation Drugs

Felbamate(Felbatol)Gabapentin(Neurontin)


Felbamate(Felbatol) Action: Block Na & Ca channels Drug used when patient unresponsive to other

anticonvulsants Use ONLY when benefits would outweigh the adverse

effects

Gabapentin(Neurotin) Only used for partial seizures Action: Blocks Ca channels One major advantage over the other anticonvulsants:

does not affect hepatic microsomal enzymes, little drug interactions

Second-Generation Drugs

Not in your book but need to know Both been on boards in recent yrs


All of the following drugs are anticonvulsants EXCEPT which one?a. Gabapentin(Neurontin)b. Carbamazepine(Tegretol)c. Phenytoin(Dilantin)d. Nifedipine(Procardia)e. Diazepam(Valium)f. Valproic acid(Depakene)

NBQ


All of the following drugs are anticonvulsants EXCEPT which one?a. Gabapentin(Neurontin)b. Carbamazepine(Tegretol)c. Phenytoin(Dilantin)d. Nifedipine(Procardia) CCBe. Diazepam(Valium)f. Valproic acid(Depakene)

NBQ


Which of the following anti-epileptic drugs decreases doxycycline levels?a. Primidoneb. Levetiracetamc. Phenytoin(Dilantin)d. Valproic acid(Depakene)

NBQ


Which of the following anti-epileptic drugs decreases doxycycline levels?a. Primidoneb. Levetiracetamc. Phenytoin(Dilantin)d. Valproic acid(Depakene)

NBQ


Which of the following anti-epileptic drugs increases incidence of gingival enlargement?a. Phenobarbitalb. Lamotriginec. Carmazepined. Phenytoine. Depakenef. Ethosuximide

NBQ


Which of the following anti-epileptic drugs increases incidence of gingival enlargement?a. Phenobarbitalb. Lamotriginec. Carmazepined. Phenytoine. Depakenef. Ethosuximide

NBQ


Which of the following anti-epileptic drugs can also be used in the treatment of trigeminal neuralgia?a. Phenobarbitalb. Lamotriginec. Carmazepined. Phenytoine. Tegretolf. Primidone

NBQ


Which of the following anti-epileptic drugs can also be used in the treatment of trigeminal neuralgia?a. Phenobarbitalb. Lamotriginec. Carmazepined. Phenytoine. Tegretolf. Primidone

NBQ

Documents

Chapter 16:Anticonvulsants DH206: Pharmacology Lisa Mayo, RDH, BSDH Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved