Anticonvulsants Flashcards
Topiramate/Topamax
Ind
Char
Migraine prophylaxis
Epilepsy (kids & adults)
Bipolar disorder
Counteract weight gain of antidepressants
Other off-label uses: essential tremor, bulimia, OCD, alcoholism, smoking cessation, neuropathic pain, cluster HA, cocaine dependence, borderline personality d/o
Phenobarbital/Phenobarb
CLass IND moa Se CHar
Barbiturate anticonvulsant
Generalized seizures
Enhances GABA activity
CNS depression, drowsiness, nystagmus
Lower IQ scores in kids w/ chronic tx
IV/PO Relatively slow onset (> 30 min), very long ½ life (>50 hr) M/b initial drug of choice in kids Metabolism: P450 enzymes Rarely used today d/t sedation
Injections can stop acute convulsions or status, but benzo is usually used
Primidone/Mysoline CLass ind moa se char
Barbiturate anticonvulsant
All types of seizures except absence
Exact MOA unknown
Phenobarbitol = known metabolite of Primidone GABA-mediated inhibition = probably chief MOA
Nausea, anorexia, HA, vertigo, ataxia
PO
Liver metabolism
½ life of metabolites: >48 hours
Category D – teratogenic, don’t use unless life-threatening condition
Can add to monotherapy if necessary
Diazepam/Valium
class
ind
moa
Benzodiazepine anticonvulsant
Grand mal seizures
Status epilepticus
Anxiety, panic disorder
Seldom ever used as 1st line tx choice (abuse potential)
Increased sensitivity of GABA-R to GABA w/ subsequent increased chloride influx
Inhibits CNS synaptic transmission
Clonazepam/Klonipin
Class ind moa se char
Benzodiazepine anticonvulsant
Alternative to Ethosuximide or Valproic acid for absence seizures
Status epilepticus
Similar to Diazepam
Drowsiness, altered mentation, addictive w/ CNS depressants, marked abuse potential
PO
Long-acting
Tolerance develops
Phenytoin/Dilantin class ind moa se char
Anticonvulsant
Prophylaxis for all seizure types except absence
Reduces Na+ & Ca2+ currents across neuronal membranes
Gingival hyperplasia
Nystagmus
Ataxia, possible hepatotoxicity, possible bone marrow suppression, hirsuitism, enlarged glands, teratogenicity, neuropathies
IV administration: hypotension, arrythmias
PO, IM, IV
Long half life
Liver metabolism
Tolerance develops
Can be used in head trauma to prevent seizures
Lots of drug-drug interactions
Carbamazepine/Tegretol
Anticonvulsant
Prophylaxis for all seizure types except absence
Chronic pain: trigeminal neuralgic, post-herpetic neuralgia
Schizophrenia, bipolar disorder
Similar to phenytoin in reduction of Na+ & Ca2+ currents across neuronal membranes
Vertigo, N/V, possible bone marrow suppression, aplastic anemia, agranulocytosis, thrombocytopenia, hepatitis, cardiovascular complications
PO
Induces CYP450
CI: MAOIs – increases risk of hypertensive crisis
Valproic acid
Depakote
Anticonvulsant
All seizure types, particularly absence & combined seizure conditions
Bipolar disorder, chronic pain syndromes Unknown Enhancement of GABA transmission N, insomnia, anxiety, potential for severe hepatotoxicity, antagonizes folic acid PO, IV Liver metabolism, highly protein bound
CI: pregnancy ancephaly / other neural tube defects, increased risk Autism – birth defects = 3-10x higher
Can add to mono therapy if absolutely necessary – additive anti-seizure effects when combined w/ other anticonvulsants
Ethosuximide
Zarontin
Anticonvulsant Absence seizures Unknown Possibly affects T-type Ca2+ channels Gingival hyperplasia Lupus-like syndrome HA, N/V, fatigue, ataxia, blurred vision, confusion, skin rash, insomnia, possible hepatotoxicity
Rare: agranulocytosis, aplastic anemia, thrombocytopenia
PO
Liver metabolism, not protein bound
Increases phenytoin levels
1st line tx for absence seizures b/c usually less hepatotoxic than Valproic acid
Gabapentin
Neurontin
Anticonvulsant
Atypical analgesic
Partial seizures: adjunctive tx
Chronic pain syndromes (post-herpetic neuralgia)
Migrains
Appears to potentiate GABA & affect N-type Ca2+ channels
Study: halts formation of new synapses
Somnolence, dizziness, ataxia, HA, other CNS SE
Can be added to monotherapy
Reduce dose w/ renal dysfunction
CI: antacids – decreases absorption of Gabapentin
Off-label: diminish desire for meth, cocaine, EtOH … not FDA approved in US
Lamotrigine
Lamictal
Anticonvulsant
Tonic-clonic (grand mal) seizures, complex partial seizures, seizures resistant to other drug tx
Bipolar disorder
Unknown
May stabilize neurons by decreasing sensitivity to excitatory effects of glutamate & aspartate
Dizziness, HA, rashes, diplopia, somnolence, ataxia
PO
Liver metabolism
Pregnancy Category C
First drug approved by FDA for bipolar disorder since Lithium (30 years earlier)
Levetiracetam
Keppra
Anticonvulsant
Tonic-clonic (grand mal) seizures, complex partial seizures, seizures resistant to other drug tx
Neuropathic pain
Unknown
May stabilize neurons by inhibition of Ca2+ movement through presynaptic channels
Generally well tolerated
Drowsiness, weakness, unsteady gait, coordination problems, HA, mood change, nervousness, loss of appetite, vomiting, diarrhea, constipation
Rare: changes in skin pigmentation
PO
Liver metabolism
Maybe: Tourette’s, autism, Alzheimer’s, bipolar
