info about epileptic drugs Flashcards

1
Q

what are some indications of carbamazepine?

A

focal seizures, tonic-clonic seizures, diabetic neuropathy, bipolar, alcohol withdrawal

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2
Q

which indications must you AVOID prescribing carbamazepine for? why?

A
all other generalised seizures that are not tonic-clonic
eg
absence
myoclonic
atonic&clonic

it will worsen them

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3
Q

what is the prescribing and dispensing info for carbamazepine when indicated for epilepsy?

A

stick to the same brand

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4
Q

what is the pt and carer advice for carbamazepine?

A

can cause hepatic, blood and skin disorders

report if u get symptoms of blood disorders [ulcer, bruising, fever, rash, bleeding]

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5
Q

what is the plasma concentration range of carbamazepine that will provide OPTIMUM results?

when should plasma conc be measured?

A

4-12mg/L

[20-50micromol/L]

measured after 1-2 weeks

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6
Q

what are the toxicity signs of carbamazepine?

A

HAND BAG

hyponatraemia
ataxia [affects balance and co-ordination]
nystagmus [involuntary movements of eyes]
drowsiness

blurred vision
arrhythmia
GI disorders

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7
Q

what is a serious side effect of lamotrigine and when does it normally occur?

A

serious skin reactions [esp in children]
serious skin rash: stevens-johnson syndrome

usually occurs in first 8 weeks

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8
Q

which anti-epileptic drug increases the plasma conc of lamotrigine

A

valproate

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9
Q

what is the pt and carer advice for lamotrigine?

A

withdraw if rash or hypersensitivity develops and see GP

report signs of blood disorder

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10
Q

what are the prescribing and dispensing information regarding phenytoin?

A

preparations are not bioequivalent. phenytoin sodium [injections/caps] not the same as phenytoin base [liquids]

prescribe same brand each time

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11
Q

what is the MHRA warning of phenytoin?

A

risk of suicide thoughts and behaviours [with all anti-epileptics]
risk of severe harm from error with injectable phenytoin
maintain pt on same brand

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12
Q

which route of administration should NOT be used with phenytoin?

A

iM route

use IV

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13
Q

which supplements should you consider [and for which types of patients] in those taking phenytoin?

A

vitamin D for those immobilised for long time or with inadequate sun exposure

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14
Q

what is the MHRA warning of phenytoin?

A

discontinue and report if signs of blood disorder develop

report if rash occurs

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15
Q

what is the target plasma concentration range for phenytoin?

A

10-20mg/L

40-80micromol/L

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16
Q

what are the toxicity signs of phenytoin? [5]

A
nystagmus
slurred speech
ataxia
confusion
HYPERglycaemia
17
Q

what are the serious interactions with phenytoin? [8]

A
  • miconazole: increases phenytoin toxicity
  • amiodarone: increases conc of phenytoin
  • DOACS: phenytoin decreases their exposure
  • carbamazepine: phenytoin decreases its conc
  • valproate: phenytoin decreases its conc
  • CHC & progesterone: phenytoin decreases their efficacy
  • ciclosporin: phenytoin decreases their conc
  • bupropion and buspirone: phenytoin decreases their exposure
18
Q

what are the side effects of PHENYTOIN?

A

PHENYTOIN

p-  p45 inducer
h - hirsutism [growth of hair on womans face/head]
e - enlarged gums [gingival hyperplasia]
ny - nystagmus/ataxia/vertigo etc
t- teratogenic
o- osteopenia
i - interferes with folic acid
n - neuropathy
19
Q

what are the serious side effects that can occur with topiramate?

A

cleft palate

myopia [short sightedness] with secondary angle-closure glaucoma. report any visual issues. seek specialist if you get intra-ocular pressure

20
Q

what should patients on ethosuximide report signs of/

A

bone marrow suppression

21
Q

what must a prescription for clobazam be endorsed with?

A

endorsed with SLS

22
Q

what is the MHRA warning of gabapentin?

A

risk of respiratory depression even without opioid drugs

adjust doses in pt with resp depression

23
Q

what cd schedule is gabapentin in?

A

schedule 3

24
Q

what must you observe pt taking gabapentin with and what is the advise that you must give them?

A

observe for signs of abuse/dependance

let them know that it can interact with alcohol and other drugs that cause CNS depression like opioids

25
what are the Important safety warnings regaring sodium valproate?
- risk of suicidal thoughts/behaviours [with all anti-epileptics] - spontaneous adverse reactions when switching a pt between diff brands - contraindicated in women with child bearing potential unless PPP is met
26
is sodium valproate an inhibitor or inducer and what does this mean?
inhibitor - increases conc of other drugs
27
which are stronger: inducers or inhibitors?
inducers
28
which types of patients should vitamin D supplementation be considered in and why?
pt who have been immobilised for long times or who have had inadequate sun exposure or reduced dietary intake of calcium bc sodium valproate can reduce bone density, also correcting vitamin D deficiency reduces seizure risk
29
what are the side effects of sodium valproate?
valproate ``` valproate appetite increased [weight gain] liver failure pancreatitis and p45 inhibitor reversible hair loss oedema ataxia teratogenicity and tremor encephalopathy [brain damage] ```
30
what are the important interactions with sodium valproate? [6]
- lamotrigine: valproate increases its conc and can cause stevens johnson syndrome [more likely in chinese and thai]. monitor rash and adjust dose of lamotrigine - phenytoin: phenytoin decreases conc of valproate and valproate increases conc of phenytoin - pivmecillinam: increases risks of s/e - topiramate: increases sodium valproate toxicity - olanzapine: increases risk of s/e - ertapenem, imipenem, meropenem: avoid. decreases conc of valproate
31
what is the pt and carer advice for sodium valproate?
- warn pt to report signs of blood, hepatic disorder and pancreatitis - make sure women have a patient card and all important info like leaflets etc
32
what is vigabatrin indicated for?
focal seizures
33
what is the serious side effect of vigabatrin? what should patients report?
visual disturbances report any visual symptoms asap