Dental Anticonvulsants Flashcards

1
Q

Traditional Antiepileptic Drugs

A

Phenobarbital (Luminal)

Phenytoin (Dilantin, Diphenylan)

Carbamazepine (Tegretol, Carbatrol)

Ethosuximide (Zarontin)

Valproic Acid (Depakote, Depakene)

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2
Q

Newer Antiepileptic Drugs

A

Gabapentin (Neurontin)

Pregabalin (Lyrica)

Oxcarbazepine (Trileptal)

Lamotrigine ( Lamictal)

Topiramate (Topomax)

Levetiracetam (Keppra)

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3
Q

Epileptic seizures

A

short term alteration in behavior due to disordered, synchronous, rhythmic firing of brain neurons

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4
Q

Partial (Focal)

A

Begin focally in a single site in cortex

Simple - preservation of consciousness, e.g. focal motor, jacksonian, somatosensory 20-60 sec

Complex - gradual loss of consciousness, may being w/ simple seizure, hallucination or strong emotions, may be followed by automatisms; lip smacking, hand wringing, 30 sec - 2 min

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5
Q

Generalized

A

involve both hemispheres of cortex from the beginning

Absence (petit mal) - (<30 sec) sudden impaired consciousness, staring, blinking, thalmic T-type Ca channels responsible for 3Hz spikes

Tonic-clonic (grand mal) - sudden impaired consciousness, 20 sec muscle rigidity then 1-2 min violent rhythmic body and limb movements

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6
Q

Secondarily generalized

A

starts with single focus area of the brain and then excites the hypothalamus and causes a generialized seizures

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7
Q

Anti-Epileptic Drug (AED) - MECHANISM OF ACTION

(Know this)

A

All drugs act to reduce neuronal activity, this also why some of these drugs are also used off label for controlling pain, bipolar disorder, etc.

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8
Q

Correct diagnosis of seizure type must occur prior to initiating drug therapy

A

Abscence seizures - ethosuximide and valproic acid - ONLY

Exacerbating abscence and myoclonic seizure - phenytoin, cabamazepine, gabapentin, tiagabine, oxcarbazepine, pregabalin and viagabatrin

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9
Q

Phenobarbital 1912 (Luminal)

A

monotherapy generialized tonic-clonic and partial seizures, IV formulation for status epilepticus

side effects - sedation in adults, irritability/hyperactivity in children (why pheno is no first line medication)

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10
Q

Phenobarbital 1938 (Dilantin, Diphenylan)

A

monotherapy generialized tonic-clonic and partial seizures; IV fosphenytoin for treatment of stat. epi.

side effects - GINGIVAL HYPERPLASIA AND STEVENS-JOHNSON SYNDROME

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11
Q

Steven-johnson syndrome (SJS)

A

<10% surface area, 5% mortality

adverse, immune system-mediated, drug reaction (not just anticonvulsants) characterized by blistering of skin and mucous

starts as a flu w/ presistent fever progressing to blisters then sloughing off of skin

treatment, discontinuation of use of suspected drug, immunosuppressives

toxic epidermal necrolysis (TEN) >30% SA, 20-40% mortality

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12
Q

Carbamazepine 1974 (tegretol, carbatrol)

A

monotherapy generialized tonic-clonic and partial seizures

side effects -

acute: stupor, coma, hyperirritability convulsions.
chronic: drowsiness, vertigo, ataxia, blurred vision. Induces CYP3A4 resulting in increased drug metabolism (e.g. oral contraceptives)

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13
Q

Oxcarbazepine 2000 (trileptal)

A

became generic oct 2007, structurally similar to carbamazepine

phamakokinectics - does not autoinduce like carbamazepine

side effects - increased drug metabolism (e.g. oral contraceptives)

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14
Q

Ethosuximide 1960 (Zarontin)

A

monotherapy abscence seizures

mechanism of action - inhibit T-type Ca channels

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15
Q

Valproic acid 1978 (Depakote, Depakene)

A

monotherapy abscence, myoclonic, partial and tonic/clonic seizures, IV formulation; broad spectrum AED

MOA - inhibit T-type Ca channels, prolong inactivation of Na channels, increase GABA synthesis (in vitro)

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16
Q

Newer AEDs - general points

A

lack serious side effects

do not induce liver enzymes

less efficacious than the traditional AEDs, approved for adjunctive treatment mostly

less is known about mechanism of action

17
Q

Gabapentin 1993 (neurontin)

A

GABA molecule bound to lipophilic hexane ring - does not appear to interact with GABA receptors, but it does suppress neuronal activity

use - neuropathic pain

pharmacokinetics - not metabolized, excreted unchanged in urine

pregabalin (lyrica) - GABA molecule

18
Q

Lamotrigine 1994 (Lamictal)

A

Broad spectrum AED

19
Q

Topiramate 1996 (Topomax)

A

Use - adjunctive treatment for partial w/ and w/o generalized tonic/clonic seizures, LGS. Broad spectrum AED

20
Q

Levetiracetam - 1999 (Keppra)

A

IV preparation for status epilepticus

Pharmacokinetics - 65% excreted unchanged in urine, no liver enzyme induction, highest safety margin in animal studies, rapid dose titration useful for adjunctive therapy

21
Q

Status epilepticus

A

series of seizures (any type) where full recovery from one seizure does not occur before onset of next seizure

Alternatives to fosphenytoin are available; levetiracetam (may be better than benzo.), phenobarbital, valproic acid