Epilepsy Drugs Flashcards
Ethosuximide Use:
1st line Absence
Ethosuximide mech:
Blocks thalamic T-type Ca++ channels
Ethosuxmide SE:
GI, Fatigue, headache, urticaria, Steven-Johnson syndrome. EFGHIJ
Benzodiazepines (diazepam, lorazepam) clinical use?
1st line for acute Status epilepticus; Also for eclampsia seizures (MgSO4 is first line)
Benzodiazepine mech
Increase GABA(A) action
Benzodiazepine SE
Sedation, Tolerance, Dependence, Respiratory Depression
Phenytoin clinical Use:
First Line Tonic-Clinic. First Line-prophylaxis for Status Epilepticus. Also Treats Simple and Complex Seizures
Phenytoin mech
Increase Na+ channel inactivation; zero-order kinetics
Phenytoin SE:
Nystagmus, diplopia, ataxia, sedation, gingival hyperplasia, hirsutism, peripheral neuropathy, megaloblastic anemia, teratogenesis (fetal hydantoin syndrome) SLE-Like syndrome, induction of CYP-450, lymphadenopathy, Stevens-Johnson Syndrome, Osteopenia
What do you use for parenteral Use?
Fosphenytoin
Carbamazepine Clinical use?
First line for Simple, Complex, and Tonic-clonic. Also first line for trigeminal neuralgia
Carbamazepine mech
increase Na channel inactivation
Carbamazepine SE
Diplopia, ataxia, blood dyscrasias (agranulocytosis, aplastic anemia), liver toxicity, teratogenesis, induction of CYP 450-, SIADH, Stevens-Johnson syndrome.
Valproic Acid clinical use?
First line Tonic-Clonic. Also used to treat Simplex, Complex, Tonic-Clonic, Absense. Also used for myoclonic seizures and bipolar disorder.
Valproic Acid Mech:
Increase Na+ channel inactivation, Increase GABA concentration by inhibiting GABA transaminase
Valproic Acid SE:
GI, distress, rare but fatal hepatotoxicity (measure LFTs), neural tube defects in fetus (spina bifida), tremor, weight gain, contraindicated in pregnancy.
Gabapentin Clinical use?
Simple, Complex, Tonic-Clonic Seizures. Also used for peripheral neuropathy, postherpetic neuralgia, migraine prophylaxis, bipolar disorder.
Gabapentin Mech:
Primarily inhibits high voltage activated Ca++ channels; designed as GABA analog
Gabapentin SE:
Sedation, Ataxia
Phenobarbital clinical use:
Simple, Complex, Tonic-Clonic
Phenobarbital Mech:
Increase GABA (A) action
Phenobarbital SE:
Sedation, tolerance, dependence, induction of CYP450, cardiorespiratory depression.
What drug is 1t line for neonates?
Phenobarbital
Topiramate Clinical use:
Simple, Complex, Tonic-Clonic. Also used for migraine prevention.
Topiramate SE:
sedation, mental dulling, kidney stones, weight loss
Topiramate mech:
blocks Na+ channels, increase GABA action
Lamotrigine clinical use:
Simple, Complex, Tonic-Clonic, Absence
Lamotrigine mech:
Blocks voltage-gated Na+ channels
Lamotrigine SE:
Stevens-Johnson syndrome (must be titrated slowly)
Levetiracetam clinical use:
Simple, Complex, Tonic-Clonic
levetiracetam mech
Unknown; may modulate GABA and glutamate release
Tiagabine clinical use:
Simple and Complex
Tiagabine mech
increase GABA by inhibiting re-uptake
Vigabatrin clinical use:
Simple and Complex
Vigabatrin mech
Increase GABA by irreversibly inhibiting GABA transamination.
What is the presentation of Stevens-Johnson syndrome?
Prodrome of malaise and fever followed by rapid onset of erythematous/purpuric macules (oral, ocular, genital). Skin lesions progress to epidermal and sloughing.
What is the first line prophylaxis for Status Elipticus?
Phenytoin
What is the first line for for Simple?
Carbamazepine
What is the first line for acute status epilepticus?
Benzos (diazepam, lorazepam)
First line for Tonic - Clonic?
Phenytoin, Carbamazepine, Valproic Acid
First line for complex?
Carbamazepine
What are the barbiturates?
Phenobarbital, Pentobarbital, Thiopental, Secobarbital
What is the mech of Barbiturates?
Facilitate GABA(A) action by increasing duration of Cl- channel opening, thus decrease neuron firing (barbiDURATES increase duration).
Barbiturates are contraindicated in what?
Porphyria
What is the clinical use of Barbiturates?
Sedative for anxiety, seizures, insomnia, induction of anesthesia (thiopental)
Toxicity of barbiturates?
Respiratory and cardiovascular depression (can be fatal); CNS dperession (can be exacerbated by EtOH use); dependence; drug interactions (induces CYP450). Overdose treatment is supportive (Assist respiration and maintain BP).
Benzodiazepines
Diazepam, lorazepam, triazolam, temazepam, oxacepam, midazolam, chlordiazepoxide, alprazolam.
mech of benzos?
Faciliate GABA(A) action by increasing (FREQUENCY) of Cl- channel opening. Decrease REM sleep. Most have long half-lives and active metabolites
most have long half lifes, what are the exceptions? what does this indicate?
Triazolam, oxazepam, and midazolam: short acting and therefore have a higher addictive potential.
Clinical use of benzos
Anxiety, spaticity, status epilepticus (lorazepam and diazepam), detoxification (especially alcohol withdrawal -DTs), night terrors, sleepwalking, general anesthetic (amnesia, muscle relaxation), hypnotic (insomnia)
Benzo Toxicity
Dependence, additive CNS depression effects with alcohol. less risk of respiratory depression and coma than with barbiturates.
What is the antidote for benzo toxicity?
Flumazenil (competitive antagonist at GABA benzodiazepine receptor)
What are the nonbenzodiazepine hypnotics?
Zolpidem, Zaleplon, esZopiclone. (All ZZZs put you to sleep)
Nonbenzodiazepine mech
Act via the BZ1 subtype of the GABA receptor. Effects reversed by flumazenil.
Nonbenzodiazepine clinical use:
Insomnia
Nonbenzodiazepine Toxicity
Ataxia, headaches, confusion. Short duration because of rapid metabolism by liver enzymes. Unlike older sedative-hypnotics, cause only modest day-after psychomotor depression and few amnestic effects. Decrease dependence risk than benzos
