Flashcards in Neuro - Pharmacology (Epilepsy & Psychoactive drugs) Deck (70):
Name 12 epilepsy drugs.
(1) Ethosuximide (2) Benzodiazepines (diazepam, lorazepam) (3) Phenytoin (4) Carbamazepine (5) Valproic acid (6) Gabpentin (7) Phenobarbital (8) Topiramate (9) Lamotrigine (10) Levetiracetam (11) Tiagabine (12) Vigabatrin
Name 10 epilepsy drugs used for simple partial seizures. For what other type of seizures can all 10 of these drugs be used?
(1) Phenytoin (2) Carbamazepine (3) Valproic Acid (4) Gabapentin (5) Phenobarbital (6) Topiramate (7) Lamotrigine (8) Levetiracetam (9) Tiagabine (10) Vigabatrin; Also used in partial complex seizures
Name 8 epilepsy drugs used for tonic-clonic generalized seizures.
(1) Phenytoin (2) Carbamezepine (3) Valproic acid (4) Gabapentin (5) Phenobarbital (6) Topiramate (7) Lamotrigine (8) Levetiracetam
Name 3 epilepsy drugs used for absence generalized seizures.
(1) Ethosuximide (2) Valproic acid (4) Lamotrigine
Name 2 epilepsy drugs used for status epilepticus generalized seizures.
(1) Benzodiazepines (diazepam, lorazepam) (2) Phenytoin
What is the first line epilepsy drug for simple partial seizures? For what other type of seizures is this the only first line epilepsy drug? For what type of seizures is this one of the several first line epilepsy drugs?
Carabamazepine; Complex partial seizures; Tonic-Clonic generalized seizures
What are 3 first line epileptic drugs for tonic-clonic generalized seizures?
(1) Phenytoin (2) Carbamazepine (3) Valproic acid
What is the first line epileptic drug for absence generalized seizures?
Ethosuximide; Think: "ethoSUXimide = SUCKS to have Silent (absence) Seizures"
What is the first line epileptic drug for acute status epilepticus generalized seizures? What is the first line epileptic drug for prophylaxis against status epilepticus generalized seizures?
Benzodiazepines (diazepam, lorazepam); Phenytoin
What is the mechanism of Ethosuximide?
Blocks thalamic T-type Ca2+ channels
For what type of seizure is Ethosuximide the first line epileptic drug?
Absence generalized seizures; Think: "ethoSUXimide = SUCKS to have Silent (absence) Seizures"
What are 5 side effects of ethosuximide?
(1) GI (2) Fatigue (3) Headache (4) Urticaria (5) Steven-Johnson syndrome; Think: "EFGHIJ - Ethosuximide causes Fatigue, GI distress, Headache, Itching, and Stevens-Johnson syndrome"
What is the mechanism of Benzodiazepines?
Increase GABAa action
What are 4 side effects of Benzodiazepines?
(1) Sedation (2) Tolerance (3) Dependence (4) Respiratory depression
For what type of seizures are Benzodiazepines used as first line epileptic drugs, and in what context?
Status epilepticus generalized seizures; First line for acute
For what other type of seizures (other than status epilepticus) are Benzodiazepines used? What is the first line drug used in this type of seizures?
Also for eclampsia seizures (1st line is MgSO4)
What are 2 examples of Benzodiazepines that can be used in status epilepticus?
What is the mechanism of Phenytoin? What kind of kinetics does it have?
Increase Na+ channel inactivation; Zero-order kinetics
What are 13 side effects of phenytoin?
(1) Nystagmus (2) Diplopia (3) Ataxia (4) Sedation (5) Gingivial hyperplasia (6) Hirsuitism (7) Peripheral neuropathy (8) Megaloblastic anemia (9) Teratogenesis (fetal hydantoin syndrome) (10) SLE-like syndrome (11) Induction of cytochrome P-450 (12) Lymphadenopathy (13) Stevens-Johnson syndrome (14) Osteopenia
What type of phenytoin is used parenterally?
Fosphenytoin for parenteral use
In what type of seizures is phenytoin used as a first line epileptic drug for prophylaxis? In what other type of seizures is phenytoin used as a first line epileptic drug?
Status epilepticus generalized seizures (prophylaxis); Tonic-clonic generalized seizures
What is the mechanism of Carbamazepine?
Increase Na+ channel inactivation
What are 8 side effects of Carbamazepine?
(1) Diplopia (2) Ataxia (3) Blood dyscrasias (agranulocytosis, aplastic anemia) (4) Liver toxicity (5) Teratogenesis (6) Induction of cytochrome P-450 (7) SIADH (8) Stevens-Johnson syndrome
What epileptic drug is the first line for trigeminal neuralgia? For what types of seizures is this epileptic drug also used as a first line?
Carbamazepine; Simple partial seizures, Complex partial seizures, and Tonic-clonic generalized seizures
What is the mechanism of Valproic acid?
Increase Na+ channel inactivation, Increase GABA concentration by inhibiting GABA transaminase
What are 6 toxicities associated with Valproic acid?
(1) GI (2) Distress (3) Rare but fatal hepatotoxicity (measure LFT's) (4) Neural tube defects in fetus (spina bifida) (5) Tremor (6) Weight gain
For what condition is Valproic acid contraindicated?
Contraindicated in pregnancy
Besides its use is simple/complex partial and/or tonic-clonic/absence generalized seizures, what are 2 other clinical uses for Valproic acid?
Also used for myoclonic seizures, bipolar disorder
What is the mechanism of Gabapentin? How is it designed?
Primarily inhibits high-voltage-activated Ca2+ channels; Designed as GABA analog
What are 2 toxicities associated with Gabapentin?
(1) Sedation (2) Ataxia
Other than seizures, what are 4 clinical uses for Gabapentin?
Also used for (1) peripheral neuropathy, (2) postherpetic neuralgia, (3) migraine prophylaxis, (4) bipolar disorder
What is the mechanism of phenobarbital?
Increase GABAa action
What are 5 toxicities associated with phenobarbital?
(1) Sedation (2) Tolerance (3) Dependence (4) Induction of cytochrome P-450 (5) Cardiorespiratory depression
Which epilepsy drug is first line in neonates?
What is the mechanism of topiramate?
Blocks Na+ channels, increase GABA action
What are 4 toxicities to associate with topiramate?
(1) Sedation (2) Mental dulling (3) Kidney stones (4) Weight loss
Besides seizures, what is another clinical use for topiramate?
Also used for migraine prevention
What is the mechanism of Lamotrigine?
Blocks voltage-gated Na+ channels
What is a toxicity of Lamotrigine? How is the risk of this toxicity reduced?
Stevens-Johnson syndrome (must be titrated slowly)
What is the mechanism for Levetiracetam?
Unknown; May modulate GABA and glutamate release
What is the mechanism for Tiagabine?
Increase GABA by inhibiting re-uptake
What is the mechanism for Vigabatrin?
Increase GABA by irreversibly inhibiting GABA transaminase
What characterizes Stevens-Johnson syndrome at initial onset? To what symptoms/signs does it progress?
Prodome of malaise and fever followed by rapid onset of erythematous/purpuric macules (oral, ocular, genital). Skin lesions progress to epidermal necrosis and sloughing.
What are 4 examples of Barbiturates?
(1) Phenobarbital (2) Pentobarbital (3) Thiopental (4) Secobarbital
What is the mechanism of Barbiturates?
Facilitate GABAa action by increasing duration of Cl- channel opening, thus decrease neuron firing; Think: "BarbiDURAtes increase DURAtion"
In what condition are Barbiturates contraindicated?
Contraindicated in porphyria
What are 4 clinical uses for Barbiturates?
Sedative for anxiety, seizures, insomnia, induction of anesthesia (thiopental)
Which Barbiturate is used as induction of anesthesia?
What are 2 potentially fatal toxicities of Barbiturates?
Respiratory and cardiovascular depression (can be fatal)
Which toxicity of Barbiturates can be exacerbated by EtOH use?
CNS depression (can be exacerbated by EtOH use)
What are 5 toxicities of Barbiturates?
(1) Respiratory and (2) Cardiovascular depression (can be fatal); (3) CNS depression (can be exacerbated by EtOH use); (4) Dependence; (5) Drug interactions (induces cytochrome P-450)
What is the treatment of Barbiturates overdose?
Overdose treatment is supportive (assist respiration and maintain BP)
Name 8 Benzodiazepines.
(1) Diazepam (2) Lorazepam (3) Triazolam (4) Temazepam (5) Oxazepam (6) Midazolam (7) Chlordiazepoxide (8) Alprazolam
What is the mechanism of Benzodiazepines?
Facilitate GABAa action by increasing frequency of Cl- channel opening; Think: "FREnzodiazepines increase FREquency"
What effect do Benzodiazepines have on the sleep cycle?
Decrease REM sleep
What kind of half-lives and metabolites do most benzodiazepines have? What are the exceptions to this rule, and why?
Most have long half-lives and active metabolites (exceptions: triazolam, oxazepam, and midazolam are short acting --> higher addictive potential)
What are 8 clinic uses for benzodiazepines?
(1) Anxiety (2) Spasticity (3) Status elipeticus (lorazepam and diazepam) (4) Detoxicification (especially alcohol withdraw-DTs) (5) Night terrors (6) Sleepwalking (7) General anesthetic (amnesia, muscle relaxation) (8) Hypnotic (insomnia)
Which 2 benzodiazepines are used for status epilepticus?
Status epilepticus (lorazepam and diazepam)
What are 2 toxicities associated with benzodiazepines? Give specific context where/if needed.
(1) Dependence (2) Additive CNS depression effects with alcohol
What is an advantage of benzodiazepines over barbiturates?
Less risk of respiratory depression and coma than with barbiturates
What is the treatment for benzodiazepine overdose?
Treat overdose with flumazenil (competitive antagonist at GABA benzodiazepine receptor)
What is GABAa receptor? Name 3 substances that bind GABAa receptor.
Benzos, barbs, and EtOH all bind GABAa receptor, which is a ligand-gated Cl- channel
What are 3 examples of Nonbenzodiazepine hypnotics?
(1) Zolpidem (Ambien) (2) Zaleplon (3) esZopiclone; Think: "All ZZZs put you to sleep"
What is the mechanism of nonbenzodiazepine hypnotics?
Act via the BZ1 subtype of the GABA receptor
What reverses the effects of nonbenzodiazepine hypnotics?
Effects reversed by flumzenil.
What is the clinical use for nonbenzodiazepine hypnotics?
What are 3 main toxicities associated with nonbenzodiazepine hypnotics?
(1) Ataxia (2) Headaches (3) Confusion
What kind of duration do nonbenzodiazepine hypnotics have, and why?
Short duration because of rapid metabolism by liver enzymes
How do nonbenzodiazepine hypnotics differ from older sedative-hypnotics?
Unlike older sedative-hypnotics, cause only modest day-after psychomotor depression and few amnestic effects