Anti-seizure Drugs Flashcards
types of seizures
- simple partial seizures: preserved consciousness
- complex partial seizures: impaired consciousness; with psychological symptoms
- generalised tonic clonic seizures = grand mal seizures
- absence seizures = petit mal; impaired consciousness
- myoclonic seizures
- status epilepticus: series of seizures without recovery of consciousness between attacks
receptors affected by anti-seizure drugs: phenytoin carbamazepine valproic acid phenobarbital topiramate
phenytoin: Na
carbamazepine: Na, glutamate
valproic acid: Na, Ca, GABA, NMDA
phenobarbital: Na, GABA, glutamate
topiramate: Na, Ca, GABA, glutamate, carbonic anhydrase
tradition anti-seizure drug
anti-convulsant (hydantoin)
blocks voltage-gated Na channels
SE: GINGIVAL HYPERPLASIA, hirsutism, anemias, teratogen (fetal hydantoin syndrome)
POTENT INDUCER OF CYP450 ENZYMES
FOLLOWS ZERO-ORDER KINETICS AT HIGH DOSES
phenytoin = diphenyl-hydantoin
fosyphenytoin, mephenytoin, ethotoin
what comprises fetal hydantoin syndrome?
upturned nose
mild mid-facial hypoplasia
long upper lip with thin vermillion border
lower distal digital hypoplasia
traditional anti-seizure drug anti-convulsant (tricyclic) blocks voltage gated Na channels and decreases glutamate release for TRIGEMINAL NEURALGIA (TIC DOLOREAU) POTENT INDUCER OF CYP450 ENZYMES INHIBITED BY ERYTHROMYCIN
carbamazepine
oxcarbazepine, eslicarbazepine
traditional anti-seizure drug
anti-convulsant (branched chain fatty acid)
for GENERALISED TONIC CLONIC SEIZURES, ACUTE MANIA OF BIPOLAR DISORDER
SE: HEPATOTOXICITY (infants), teratogen (NEURAL TUBE DEFECTS), SPINA BIFIDA
INHIBITOR OF CYP450 ENZYMES
Valproic Acid
sodium valproate
acts on GABA transaminase, which degrades GABA
traditional anti-seizure drug
anti-convulsant (barbiturate)
increases DURATION of CL- channel opening
SE: dependence liability greater than benzodiazepines, ACUTE INTERMITTENT PORPHYRIA
POTENT INDUCER OF CYP450 ENZYMES
PREFERRED ANTI-SEIZURE DRUG IN CHILDREN AND PREGNANT WOMEN
Phenobarbital
Primidone
traditional anti-seizure drug anti-convulsant (cyclic ureide) decreases Ca currents (t-type) in thalamus DOC FOR ABSENCE SEIZURES SE: GI distress
ethosuximide
phensuximide, methsuximide
traditional anti-seizure drug
anti-convulsant (benzodiazepine)
increases FREQUENCY of Cl- channel opening
for STATUS EPILEPTICUS
diazepam
lorazepam, clorazepate
traditional anti-seizure drug
anti-convulsant (benzodiazepine)
increases FREQUENCY of Cl- channel opening
for INFANTILE SPASMS
clonazepam
clobazam
traditional anti-seizure drug
anti-convulsant (GABA derivative)
for NEUROPATHIC PAIN (POST-HERPETIC NEURALGIA), MIGRAINE
gabapentin (enhances GABA)
pregabalin
traditional anti-seizure drug anti-convulsant (phenyltriazine) blocks Na and Ca channels decreases glutamate SE: STEVEN JOHNSON SYNDROME
lamotrigine
traditional anti-seizure drug
anti-convulsant (piracetam)
selectively binds vesicular protein SV2A
SE: PSYCHOSIS (due to decreased dopamine levels, schizophrenia develops)
levetiracetam
traditional anti-seizure drug
anti-convulsant (monosaccharide derivative)
multiple actions on synaptic function (Na, Ca, GABA, AMPA-glutamate, carbonic anhydrase)
for: Lennox-Gestaut Syndrome, West Syndrome
SE: PSYCHOMOTOR SLOWING, MEMORY IMPAIRMENT, WEIGHT LOSS, ACUTE MYOPIA, GLAUCOMA, UROLITHASIS
ANTI-SEIZURE DRUG WITH MOST NUMBER OF MECHANISMS OF ACTION
topiramate
DOC for generalised tonic-clonic seizures
valproic acid
phenytoin
carbamazepine
DOC for partial seizures
carbamazepine
lamotrigine
phenytoin
DOC for absence seizures
ethosuximide
valproic acid
DOC for myoclonic and atypical absence syndromes
valproic acid
status epilepticus
lorazepam
diazepam
phenytoin
phenobarbital
other clinical uses for anti-seizure drugs
- bipolar affective disorders
- trigeminal neuralgia
- neuropathic pain (post-herpetic neuralgia)
- migraine
