Anti-Epileptics

Question 1

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what is epilepsy

Answer 1

chronic condition of the brain characterized by recurrent seizures

Question 2

what is a seizure

Answer 2

a single occurence caused by abnormal neuronal disharge in one part of or the entire brain

Question 3

causes of epilepsy

Answer 3

1. increased activity of voltage-gated ion channels such as Na, K and Ca
2. increased excitatory glutmate transmission
3. decreased inhibitory GABA transmission

Question 4

target of anti-convulsants

Answer 4

1. inhibit Na channels by prolonged inactivation
2. inhibit of Ca currents in T-type Ca channels
3. increased gaba transmission
4. decreased glutamate transmission

Question 5

inhibtion of ca currents in t-type ca channels is used to treat

Answer 5

absence seizures

Question 6

inhibition of na channels is used to treat

Answer 6

focal and generalized seizures except absence seizures

Question 7

classification of anti-epileptics

Answer 7

aliphatic carboxylic acid
1. valproic acid

newer drugs
1. lamatrogine
2. topiramte

benzodizapenes
1. diazepam
2. clonazepam

iminostilbenes
1. carbamazepene

succinimides
1. ethosoxumide

barbiturates
1. phenobarbitone

hydantoins
1. phenytoin
2. fosphenytoin

Question 8

Na channel inhibitors

Answer 8

1. phenytoin
2. valproic acid
3. carbamazepine
4. lamotrigine
5. topiramate

Question 9

drug of first choice for treatment of focal and generalized seizures

Answer 9

phenytoin

Question 10

phenytoin not useful in the treatment of

Answer 10

1. absence seizures
2. infant spasms

Question 11

drug interactions of phenytoin

Answer 11

phenylbutazone and sulfonamides displace phenyotin

Question 12

drug of choice in the treatment of status epilepticus

Answer 12

IV fosphenytoin

Question 13

drug of choice for IV or IM adminitration

Answer 13

fosphenytoin

Question 14

is fosphenytoin or phenytoin more water soluble

Answer 14

• fosphenytoin more water soluble so given IV
• phenytoin less water soluble so given orally

Question 15

adverse effects of phenytoin

Answer 15

PHENYTOIN

1. purple glove syndrome (when IV)
2. hirsutism, more and coarser facial hair
3. enlarged gums (gingival hyperplasia)
4. nystahmus
5. yellowing of skin
6. teraogeniciy ie fetal hydantoin syndrome
7. osteoporosis and osteomalacia
8. interference of vit b12 absorption, causing macrocytic anemina
9. neuropathies

Question 16

fetal hyantoin syndrome

Answer 16

1. growth retardation
2. microcephaly
3. facial abnormalities such as cleft palate

Question 17

fetal hydantoin syndrome caused by

Answer 17

epioxide metabolite of phenytoin

Question 18

phenytoin causes osteoporosis due to

Answer 18

inhibtion of iron absorption

Question 19

phenytoin causes macrocytic anemia due to

Answer 19

impaired vit b12 absorption

Question 20

at high concentrations phenyotin exhibits what order of kinetics

Answer 20

zero order

Question 21

carbamazepine is the drug of choice for

Answer 21

complex partial and generalized seizures

Question 22

clinical uses of carbamazepine

Answer 22

1. complex seizures
2. trigemial neuralgia
3. bipolar disorder

Question 23

MOA of carbamazepine

Answer 23

Na channel blocker

Question 24

contraindications of carbamazepine

Answer 24

• absence or myoclonic seizures
• apalastic anermia/agranulocytosis
• rash

Question 25

MOA of Lamotrigine

Answer 25

Na channel blocker

Question 25

adverse effects of carbamazepine

Answer 25

**PATCH** 1. Potentiates ADH action - water retention and hyponatremia 2. Aplastic anemia/agranulocytosis 3. Teratogenic 4. CNS effects (diplopia, ataxia) 5. Hepatic enzyme elevation

Question 26

clinical uses of lamotrigine

Answer 26

1. simple and complex seizures 2. ABSENCE SEIZURES 3. Lennox-Gastaut Syndrome

Question 27

MOA of valproic acid

Answer 27

broad spectrum 1. Na channel blocker 2. GABA agonist 3. blocker of t type Ca channels

Question 28

contraindication of valproic acid

Answer 28

liver disease

Question 29

adverse effects of VA

Answer 29

1. NTDs 2. PCOS 3. weight gain 4. bone loss

Question 30

first line of treatment for absence seziures

Answer 30

valproic acid

Question 31

uses of VA

Answer 31

1. absence seizures 2. myoclonic 3. atonic 4. simple and complex seizures 5. mixed seizures 6. when type of seizure cannot be detected 7. photosensitive epilepsy 8. juvenile myoclonic epilepsy

Question 32

GABA agonists

Answer 32

1. Barbiturates 2. Benzodiazapenes

Question 33

second choice for treatment of simple focal or generalized seizures

Answer 33

phenobarbital

Question 34

contraindications of phenobarbital

Answer 34

absence seizures

Question 35

MOA of phenobarbital

Answer 35

increases duration of opening of GABA channels

Question 36

MOA of benzodiazepines

Answer 36

increase frequency of GABA channels opening

Question 37

examples of benzodiazepines

Answer 37

1. diazepam 2. lorazepam 3. clonazepam

Question 38

which benzodiazepine is used in the treatment of most seizures

Answer 38

clonazepam

Question 39

contraindications of benzodiazepines

Answer 39

1. (diazepam) children under 9 years 2. narrow angle glaucome

Question 40

adverse effects of bzd

Answer 40

- hypotonia - dysarthria

Question 41

dysarthria is a common side effect of which anti-epileptic

Answer 41

benzodiazepines

Question 42

which antiepileptic is contraindicated in narrow angle glaucoma

Answer 42

benzodiazepines

Question 43

ca channel blockers

Answer 43

1. ethosoxumide 2. valproic acid

Question 44

first line therapy for absence seizures

Answer 44

ethosuxumide

Question 45

first line treatment for febrile seizures

Answer 45

diazepam

Question 46

treatment of status epilepticus

Answer 46

1. IV diazepam 2. IV lorazepam 3. IV fosphenytoin 4. IV phenobarbitone