Anti-Seizure

Question 1

Epilepsy

Answer 1

group of disorders characterized by excessive neuron stimulation within the CNS. Initiated by high frequency discharge from group of excitable neurons called focus caused by congenital defects, hypoxia at birth, head trauma or brain tumors, symptoms depend on location and how discharge spreads to other portions of brain.

Question 2

Antiseizure drugs act by

Answer 2

suppressing neuronal discharge at focus and brain, mainly by inhibition of sodium and calcium influx due to binding to sodium or calcium, channels and augmenting inhibitor GABA responses

Question 3

Goal in therapy

Answer 3

reduce number and severity of seizures, allowing patient to live a normal life (ideally eliminate) may not be possible due to side effects. Promote compliance, mono therapy has fewer side effects and lower cost. Withdrawal must be done over extend dperiod of time (6 weeks to several months) if patient is receiving two drugs they must be withdrawn sequentially.

Question 4

Blockers of sodium channel

Answer 4

Carbamazepine, oxcarbazepine, lamotrigine, phenytoin, topiramate, valproic acid, zonisamide

Question 5

Calcium channel blockers

Answer 5

Ethusuximide, lamotrigine, valproic acid, zonisamid

Question 6

N methyl D aspartic acid receptor blockers

Answer 6

Felbamate

Question 7

AMPA receptor blockers

Answer 7

Topiramate

Question 8

Antiseizure agents influencing GABA

Answer 8

receptor enhancer: Phenobarbital, benzodiazepines; reuptake inhibitors: Tiagabine; degradation inhibitors: vigabatrin, valproic acid; influencing vesicle proteins Levetiracetam

Question 9

Phenytoin

Answer 9

read

Question 10

Carmazepine

Answer 10

reduces propagation of abnormal impulse in brain by blocking sodium channels, inhibiting generation of repetitive action potentials in epileptic focus ; I: partial seizures, manic depressive patients, slowly absorbed orally, enter brain rapidly bc of lipid solubility, induces drug metabolizing enymes in liver, decreases chronic administration, increases antiepileptic; AE: stupor, coma, respiratory depression, drowsiness vertigo blurred vision, nausea vomitting, liver toxicity

Question 11

Phenobarbital

Answer 11

read

Question 12

Valproic acid

Answer 12

read

Question 13

Benzodiazepines

Answer 13

I: absence and myoclonic seizures (Clonazepam), partial seizures (Clorazepate in conjunction with other drugs, acute treatment of status epilepticus (Diazepam); AE: drowsiness, somnolence, fatigue, ataxia, dizziness, behavior changes, cardiac and respiratory depression (After IV in acute)

Question 14

Gabapentin/Lamotrigine

Answer 14

Gabapentin is an analogue of GABA, exact mechanism is unknown, Lamotrigine inhibits glutamate release, blocks sodium and calcium channels and prevents repetitive firing; Gabapentin does not bind to plasma proteins and is exerted unchanged through kidneys, minimizing drug interactions while Lamotrigine is metabolized in the liver, half life decreased by enzyme inducing drugs (carbamazepine, phenytoin) and increase by valproic acid. I: simple/complex partial seizures, generalized tonic-clonic; AE: mild CNS, rash

Question 15

Benzodiazepines - anxiolytic action

Answer 15

alprazolam, chlordiazepoxide, clonazepam, diazepam, lorazepam, oxazepam

Question 16

Benzodiazepines - hypnotic action

Answer 16

flurazepam, temazepam, triazolam

Question 17

Benzodiazepines - anesthetic action

Answer 17

Midazolam

Question 18

Benzodiazepines

Answer 18

read

Question 19

Zolpidem

Answer 19

acts on subset of benzodiazepine receptor family, it is hypnotic, no anticonvulsant or muscle relaxing properties, rapidly absorbed from GI tract, short elimination of 3 hours; AE: headache, daytime drowsiness, nightmare. it has no withdrawal effects, minimal rebound insomnia and little or no intolerance with prolonged use.

Question 20

Buspirone

Answer 20

general unknown, binds to dopamine and serotonin receptors, does not bind to benzodiazepine receptors and does not have a muscle relaxant, anticonvulsant, or hypnotic activity. I: short term treatment of generalized anxiety; AE: headaches, dizziness, nervousness, little potential to develop dependences, may require 1-2 weeks for therapeutic effect to take place.

Question 21

Hydroxyzine

Answer 21

little potential to develop dependence, useful for patients with anxiety who have a history of drug abuse.

Question 22

Propranolol

Answer 22

varying doses (40-240 mg/day) only proved useful in reducing somatic symptoms of anxiety (palpitations, sweating, tachycardia)

Question 23

Meprobamate

Answer 23

depresses CNS similarly to barbiturates, especially Phenobarbital, but Meprobamate is shorter acting, capable of promoting sleep. I: anxiety, AE: drowsiness, blood dyscrasia, physical dependence

Question 24

Barbiturates

Answer 24

read

Question 25

Barbiturates - ultra short duration of action (30 minutes)

Answer 25

Thiopental

Question 26

Barbiturates - short duration of action (2 hours)

Answer 26

hexobarbital, pentobarbital, secobarbital

Question 27

Barbiturates - intermediate duration of action (3-5 hours)

Answer 27

amobarbital, butabarbital

Question 28

Barbiturates - long duration of action (more than 6 hours)

Answer 28

barbital, phenobarbital