Epilepsy Flashcards
1
Q
What is epilepsy? Describe what happens in neurons during a seizure
A
Epilepsy is diagnosed when a patient suffers repeated epileptic seizures. Seizures are sudden episodes of abnormal bursts of excitatory brain activity, leading to transient motor, autonomic, psychic, or sensory dysfunction.
2
Q
List 3 possible causes of epilepsy?
A
Inherited component
Non-structural metabolic causes e.g. related to alcohol abuse or hypoglycaemia.
Physical damage to part of the brain e.g. caused by trauma, ischaemia (brain cell death due to inadequate oxygen supply as in stroke) or tumours
3
Q
List the major seizure categories including 2 types of seizures from each
A
Focal/ Partial seizures
Generalised seizures: Tonic-clonic Absence Myoclonic Atonic and Tonic
Status epilepticus
4
Q
What is the main aim of treatment in epilepsy?
A
Prevent the occurrence of seizures while minimising unwanted effects. Maximise quality of life
5
Q
List the 3 primary mechanisms of action of antiepileptic drugs
A
- Decreased sustained high frequency firing of action potentials
e. g. carbamazepine, gabapentin, lamotrigine, phenytoin, topiramate, and possibily sodium valproate - Increases GABA influence
- Blockage of the T-type Ca2+ channels
e. g. Ethosuximide
6
Q
What should be considered when deciding on treatment? (5)
A
Seizure type Age Sex Concomitant medicines Co-morbidity
7
Q
Give some examples of anti-epileptics with a long half life?
A
Lamotrigine
Perampanel
Phenytoin
Phenobarbital
8
Q
How do you change from one drug to another?
A
Slowly withdrawing first line treatment once new regime is established
9
Q
MHRA (2013) - maintaining patients on the same brand. Medicines are categorised into 3 groups. Which ones are included in each?
A
Category 1: ensure same brand Phenytoin Carbamazepine Phenobarbital Primidone
Category 2: based on clinical judgement if need to keep on same brand Valproate Lamotrigine Perampanel Rufinamide Clobazam Clonazepam Oxacarbazepine Eslicarbazepine Zonisamide Topiramate
Category 3: unnecessary to keep same brand unless there is concern e.g. patient anxiety, risk of dosing errors Levetiracetam Lacosamide Tiagabine Gabapentin Pregabalin Ethosuximide Vigabatrin
10
Q
What is anti-epileptic hypersensitivity syndrome and what are the symptoms?
A
Rare but potenially fatal syndrome associated with some anti-epileptics
Symptoms - show 1-8 weeks after exposure
Fever, Rash, Lymphadenopathy
Liver dysfunction
haematological, renal and pulmonary abnormalities, multi organ failure.
11
Q
Which medicines is Anti-epileptic hypersensitivity syndrome associated with? (8)
A
Carbamazepine Lacosamide Lamotrigine Oxacarbazepine Phenobarbital Phenytoin Primidone Rufinamide
12
Q
What is the MHRA (2008) regarding anti-epileptics?
A
Increased risk of suicidal thoughts and behaviour
13
Q
How should anti-epileptics be withdrawn and what is there a risk of?
A
Slowly - risk of seizure recurrence
especially with barbiturates and benzodiazepines
14
Q
What must a patient who drives do if they have a seizure of any type?
A
Inform the DVLA and stop driving
15
Q
How long do patient’s who have had an unprovoked/single isolated seizure have to wait for before being able to drive again? What must they be cleared of?
What if a patient has established epilepsy?
A
6 months
Can resume once they have been assessed as fit to drive and do not suggest future risk
Established - CAN drive if they are not a danger to public, compliant with meds and follow up. Must be seizure free for at least 1 year & have a history of unprovoked seizures.
16
Q
If a patient has had a seizure whilst asleep, how long do they have to wait before driving again?
A
1 year from the date of each seizure unless:
a history or pattern of sleep seizures has been established over 1 year from date of first sleep seizure.
OR
established pattern of purely asleep seizures ove3 years if pt has previously had seizures whilst awake.
17
Q
When else does the DVLA advise that patients should not drive during…
A
During medication changes or withdrawal.
Wait 6 months after last dose.
18
Q
Outline treatment summary of FOCAL/PARTIAL seizures with or without generalisation
1st/2nd/Adjunct/Tertiary
A
1st line:
Carbamazepine
Lamotrigine
2nd:
Oxacarbazepine
Sodium Valproate
Levetiracetam
If monotherapy is unsuccessful then adjunct: Carbazepine Clobazam Gabapentin Lamotrogine Levetiracetam Oxacarbazepine Sodium Valproate Topiramate
If ineffective/ not tolerated then specialist advise on tertiary options: Eslicarbazepine acetate Lacosamide Phenobarbital Phenytoin Pregabalin Tiagabine Vigabatrin Zonisamide
19
Q
Outline treatment summary of TONIC CLONIC (generalised) seizures.
1st/2nd/Adjunct/Tertiary
A
1st line: Sodium Valproate (except in females who are pre-menopausal)
2nd:
Lamotrogine
if established tonic clonic then either one (sodium val or lamo) can be prescribed
Alternative 1st line:
Carbamazepine
Oxacarbazeopine
but may exacerbate myoclonic and absence seizures
Adjunct: Clobazam Lamotrogine Levetiracetam Sodium valporate Topiramate
20
Q
Outline treatment summary of ABSENCE seizures.
1st/2nd/Adjunct
Which are not recommended?
A
1st line:
Ethosuximide
Sodium valproate (should be used esp if high risk of tonic-clonic seizures)
2nd:
Lamotrigine
Or if still not working - a combination of any two of above drugs.
NOT RECOMMENDED (same as myoclonic): Carbamazepine Gabapentin Oxacarbazepine Phenytoin Pregabalin Tiagabine Vigabatrin
21
Q
Outline treatment summary of MYOCLONIC seizures.
1st/2nd/Adjunct/Tertiary
A
1st line: Sodium Valproate (not premenopausal females)
2nd:
Topiramate (* less favourable side-effects)
Levetiracetam
Adjunct: combo of two of above drugs.
NOT RECOMMENDED (same as absence): Carbamazepine Gabapentin Oxacarbazepine Phenytoin Pregabalin Tiagabine Vigabatrin
22
Q
Outline treatment summary of ATONIC & TONIC seizures.
1st/2nd/Adjunct/Tertiary
Usually seen in childhood - associated with cerebral damage or mental retardation.
A
1st line: Sodium Valproate (except premenopausal females)
Adjunct:
Lamotrigine
Tertiary under specialist
Rufinamide
Topiramate
23
Q
For what type of seizures are these NOT RECOMMENDED for use: Carbamazepine Gabapentin Oxacarbazepine Phenytoin Pregabalin Tiagabine Vigabatrin
A
- Absence
- Myoclonic
- Atonic & Tonic
24
Q
What else is Gabapentin licensed and unlicensed for?
A
Licensed - neuropathic pain
Unlicensed - migraine prophylaxis
25
What else is Pregabalin licensed for? (2)
Neuropathic pain
| Generalised anxiety disorder
26
What are the immediate measures to manage status epilepticus? (4)
1. Positioning the patient to avoid injury
2. supporting respiration
3. maintaining blood pressure
4. correction of any hypoglycaemia
27
What should be given if alcohol abuse is suspected in status epilepticus?
Parenteral thiamine
28
What should be given if pyridoxine hydrochloride deficiency is suspected in status epilepticus?
Pyridoxine hydrochloride
29
Seizures lasting longer than 5 mins should be treated urgently with...
Intravenous Lorazepam
| repeated after 10mins if seizures resume or fail to respond
30
Intravenous diazepam can also be used for seizures lasting longer than 5mins ...but what is there a risk of?
High risk of thrombophlebitis (inflammation of a vein relating to a blood clot)
31
Why can't intramuscular or suppository diazepam be used for seizures lasting longer than 5mins?
Absorption is too slow
32
What should the patient be monitored for when giving IV diazepam or lorazepam? (2)
1. Respiratory depression
| 2. Hypotension
33
If there are no resuscitation facilities available for status epileptics ..what can be given? (2 options)
1. Diazepam - rectal solution
| 2. Midazolam - oral solution
34
What would you do if seizures didn't stop after 25mins or recur after treatment with benzodiazepines?
```
1. phenytoin
or
2. fosphenytoin sodium (phenytoin pro-drug)
or
3. phenobarbital sodium
```
35
What are the 3 indications for Carbamazepine?
2 unlicensed?
1. Focal seizures
2. Bipolar when unresponsive to lithium
3. Trigeminal neuralgia
4. Alcohol withdrawal
5. Diabetic neuropathy
36
What is the MoA of carbamazepine?
Binds to Na channels to prevent action potential
37
Important adverse effects of Carbamazepine
1. Nausea
2. Dizziness
3. Fatigue
4. GI discomfort
5. Odema
6. Hyponatraemia
7. Vomiting
8. Thrombocytopenia
9. Skin reactions - red man / rash
10. Vision disorders - nystagmus
11. Leucopenia
12. Eosinophilia
38
In which patients should carbamazepine be prescribed with caution in due to toxicity? (3)
1. Renal
2. Hepatic
3. Cardiac
39
The efficacy of anti-epileptics is reduced by drugs that lower the seizure threshold. Give 4 examples?
1. SSRIs
2. Tricyclic antidepressants
3.
4. Isoniazid ?
40
Switching between different oral formulations of carbamazepine should be avoided ...why?
Bioavailability between them differs
41
Which anti-epileptics have long half-lives so can be given once daily at bedtime? (4)
1. Lamotrigine
2. Perampanel
3. Phenobarbital
4. Phenytoin
42
Scenerio: Unplanned pregnancy & on antiepileptic. Should pt stop meds or continue?
What's the pathway of care...
Pt should continue on medication as it's too late to start the withdrawal period.
Risk of harm to mother or fetus from convulsive seizures outweighs the risk of continued therapy.
To reduce risk of neural tube defects - folate supplementation is advised before conception and 1st trimester.
Conc of antiepileptic drugs in plasma can change during pregnancy - phenytoin, carbamazepine and lamotrigine should be adjusted & others monitored.
43
What should be administered at birth to minimise risk of neonatal haemorrhage associated with antiepileptics?
Vitamin K injection
44
Newborn can experience withdrawal effects of which antiepileptic drugs? (2)
1. Benzodiazepines
| 2. Phenobarbital
45
Breastfeeding - babies should be monitored for development as well as serum levels for meds that readily pass into breast milk causing high infant serum -drug concentration. Which are they? (4)
1. Lamotrigine
2. Ethosuximide
3. Primidone
4. Zonisamide
46
Withdrawal effects can occur in infants if mother stops breast feeding suddenly -- if she is taking which meds? (3)
1. Lamotrigine
2. Primidone
3. Phenobarbital
47
Which anti epileptic should patients be warned to look out for signs of fever, rash, mouth ulcers, bruising, bleeding?
Carbamazepine
Signs of blood, hepatic or skin disorders
48
Patients should be told how to spot signs of blood disorders: fever, mouth ulcers, bruising or bleeding.
Which antiepileptics should have this advice?
Blood counts needed.
1. Ethosuximide
49
Agranulocytosis is a side effect of which antiepileptics ?
1. Ethosuximide
Look out for fever, mouth ulcers, bruising, bleeding
Phenobarbital possibly
50
What is Gabapentin used for?
1. Adjunct or monotherapy for focal seizures with or without secondary generalisation
2. Peripheral neuropathic pain
3. Menopausal symptoms, particularly hot flushes, in women with breast cancer
4. Oscillopsia and Spasticity in multiple sclerosis
51
Gabapentin is not licensed for use in children under ___ years?
or doses over __ mg/kg in children under __ years?
6 years
50mg/kg 12 years
52
What are the 3 MHRA advice for Gabapentin?
1. Antiepileptics: risk of suicidal thoughts and behaviour
2. Gabapentin (Neurontin®): risk of severe respiratory depression - high risk patients such as elderly, compromised respiratory function/disease, renal impairment etc = dose adjustment
3. Gabapentin (Neurontin®) & Pregabalin (Lyrica) and risk of abuse and dependence:
reclassified as a Class C controlled substance and is now a Schedule 3 drug, but is exempt from safe custody requirements
53
Gabapentin should be used with caution in which group of patients?
1. Diabetic mellitus
2. Elderly
3. High doses of oral solution in - Young adults/adults with low body weight
4. History of psychotic illness
5. History of substance abuse
6. Mixed seizures (including absences)
54
High doses of oral gabapentin should be used carefully in young adults/adults with low body weight (39-50kg)...why?
The levels of propylene glycol, acesulfame K and saccharin sodium may exceed the recommended WHO daily intake limits
55
Side effects of gabapentin?
Common:
1. Abnormal appetite
2. Confusion
3. GI - Constipation, Diarrhoea, Nausea, Vomiting
4. Depression
5. Cough
6. Leucopenia
7. Movement disorders, Dizziness, Nystagmus, Vertigo, Tremor
8. Sexual dysfunction
9. Visual disturbance
Uncommon
1. Cognitive impairment
2. Palpitations
Freq not known
1. AKI
2. Alopecia
3. Breast enlargement
4. Hyponatraemia
5. Suicidal tendencies (MHRA warning)
6. Tinnitus
7. Urinary incontinence
56
Gabapentin dose advice for those with renal impairment ?
Dose reduced depending on creatinine clearance
57
What drug should be used to manage febrile convulsions?
Brief febrile convulsions (resulting from high temp/ fever) require no specific treatment, just anti-pyretic medication- paracetamol!!
58
What do patients and carers need to look out for in those taking carbamazepine and phenytoin?
```
Signs of blood, hepatic or skin disorders:
Fever
Rash
Ulcers
Bruising and bleeding
```
Known as Leucopenia (low white cell count, but this is NOT the same as agranulocytosis)
59
Which anti-epileptic requires monitoring of ECG and BLOOD PRESSURE with intravenous use?
Phenytoin
60
Which antieplieptic has been associated with pancreatitis?
Sodium valproate
61
Apart from Epilepsy, what else can Lamotrigine be used for?
Monotherapy or adjunctive therapy of bipolar disorder (without enzyme inducing drugs) with/without valproate
62
What cautions are there for Lamotrigine? (2)
1. Myoclonic seizures
| 2. Parkinson's disease
63
Side effects of Lamotrigine?
1. Aggression
2. Diarrhoea, Nausea Vomiting
3. Dizziness, Drowsiness, Tremor
4. Dry mouth
5. Fatigue, Headache, Irritability
6. Pain, Athralgia (pain in joint)
7. Sleep disorder
64
Rare but serious side effects with Lamotrigine include: skin reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis (most occur in first 8 weeks). Can be associated with hypersensitivity syndrome.
What factors may be associated with this? (3)
1. Concomitant use of valproate
2. Initial lamotrigine dose higher than rec
3. More rapid dose escalation than recommended
65
Lamotrigine should be used with caution in hepatic impairment. Dose adjustment should be __%_ in moderate and __%_ in severe.
50% in moderate
75% severe
66
Lamotrigine should be used with caution in renal impairment. Why?
Metabolite may accumulate
67
Patient advice and signs to look out for with the use of lamotrigine?
Rash or signs of hypersensitivity
Anaemia, bruising or infection - signs of bone marrow failure
68
What antieplieptic requires opthalmological monitoring/ discolouration of ocular tissue/ blue- grey discolouration of nails lips and skin?
Retigabine
69
Which anti-epileptic is particularly associated with hepatic dysfunction and what are the symptoms?
Sodium valproate
Persistent vomiting, abdominal pain
Anorexia, jaundice, oedema, malaise
Monitor liver function before therapy and during first 6 months of treatment!
70
Coarsened facial appearance, acne, weight loss, constipation, dizziness, mouth tenderness, headache, nausea
All side effects of?
Phenytoin
71
In what 3 circumstances should phenytoin treatment be discontinued?
Signs of toxicity
Rash
Hepatoxicity
72
What are the signs of phenytoin toxicity?
```
Nystagmus (uncontrolled eye movement)
Diplopia (double vision)
Slurred speech
Ataxia (uncontrolled body movement)
Confusion
HYPERglyceamia
```
73
Which antieplieptic do you need to look out for symptoms of anaemia, bruising and infection?
Lamotrigine
74
Which antieplieptic has been associated with the serious skin rash, Steven Johnsons syndrome?
Lamotrigine
Usually in first 8 weeks of treatment
75
What risk does Topiramate carry in terms of harm to foetus?
Risk of Cleft palate (cleft lip)
76
Can patients with epilepsy drive a large goods or passenger carrying vehicle?
No
Only motor vehicles
However they can if they haven't had a seizure for 5 years
77
Indication for Phenytoin?
1. Tonic-clonic seizures
2. Focal seizures
3. Status epilepticus
4. Seizures associated with head trauma or neurosurgery
78
Phenytoin sodium is NOT bioequivalent to those containing phenytoin base.
How much phenytoin is the equivalent in each? What's the issue and what should be monitored?
100mg phenytoin sodium = 92mg phenytoin base
Such as Epanutin Infatabs and Epanutin suspension.
Initial dose is same for all products but it is when changing between formulations phenytoin content may be clinically significant & plasma phenytoin should be monitored.
79
MHRA Advice includes the risk of suicidal thoughts & behaviour. & switching between.
1. What is the NHS Improvement Patient Safety Alert risk for Phenytoin?
2. What category is it in for brand?
Risk of death and severe harm from error with injectable phenytoin
category 1 - keep same brand
80
What should the serum level for phenytoin be? when should it be measured?
If I wanted to change the dose - how should this be done? & why?
1. 10-20mg/L or 40-80micromol/litre
2. Immediately before the next dose
3. Small changes (e.g. 50mg) at a time as due to the zero -order kinetics even small changes can result in marked change in plasma drug conc.
81
Phenytoin is metabolised by the ..... so dose should be reduced in which patients?
Hepatic
Hepatic impairment
82
Side effects& warning signs of Phenytoin?
(5) warning
(6) side effects
mostly connected to warning points
1. Toxicity - Ataxia, Nystagmus, Hyperglycaemia, Diplopia/Blurred vision, Slurred speech, Confusion
& in IV = can cause death from respiratory depression & cardiovascular collapse.
2. Skin reactions - rash, toxic necrolysis
3. Blood disorders - fever, sore throat, unexplained bruising / bleeding, mouth ulcers, leucopenia, aplastic anaemeia & megaloblastic anaemia.
4. Suicidal thoughts
5. Low Vit D & folic acid - osteomalacia (sofenting of bones), rickets, haemotological disorders
```
1. Electrolyte imbalance
Pneumonitis
Purple glove syndrome
Arrhythmias (IV)
Agranulocytosis
Bone disorders
Insomnia
```
83
Interactions of phenytoin?
| 3 categories
Phenytoin is a P450 enzyme inducer
```
1. Conc. increases with enzyme inhibitors such as:
Amiodarone
Chloramphenicol
Cimetidine
Disulfiram
Diltiazem
Fluconazole
Fluoxetine
Miconazole
Topiramate
Trimethoprim
Metronidazole
Clarithromycin
Telithromycin (avoid during & 2 weeks after phenytoin)
```
```
2. Conc decreases with enzyme inducers such as:
Rifampicin
St Johns Wort
Theophylline
Itraconazole
Ciclosporin
```
3. Effect reduced with those that lower the seizure threshold
- SSRI
- Antipsychotics
- Tricyclic antidepressants
- Tramadol
84
What is the risk of phenytoin in pregnancy? What should the pt do if planning on pregnant>
1. Cranial abnormalities
2. Reduced IQ
Discuss with specialist and high dose folic acid before pregnancy
85
What should be monitored in Phenytoin? (6)
1. Serum concentration
2. ECG (if IV)
3. Blood pressure (if IV)
4. Iron & folate levels
5. Blood count
6. Liver function
86
What can happen with the long term use of Phenytoin? (4)
1. Coarsening skin
2. Acne
3. Hirsutism
4. Gum hypertrophy
87
Caution with phenytoin with enteral feeding. What's the advice?
What supplement should be considered for those who will be immobilised for long periods of time/ inadequate sun exposure?
1. Interrupt feeding for 2 hours and after dose. more freq monitoring necessary
2. Vit D supplementation
88
What to do if Rash occurs in pt on phenytoin?
Mild? Severe?
What about with IV use & bradycardia or hypotension occurs?
1. Discontinue
if mild - reintroduce cautiously, if reappears discontinue immediately
2. Reduce rate of administration
89
Why are Therapeutic plasma-phenytoin concentrations reduced in first 3 months of life?
What should the plasma conc for children ages be?
neonate - 3months
3months to 18years
Because of reduced protein binding.
Trough plasma concentration for optimum response: neonate–3 months, 6–15 mg/litre (25–60 micromol/ litre); child 3 months–18 years, 10–20 mg/litre (40–80 micromol/litre).
90
Indication of Levetiracetam (Keppra)?
1. Monotherapy OR Adjunctive of focal with or without secondary generalisation
2. Adjunctive therapy - myoclonic and tonic-clonic
91
MHRA advice for Levetiracetam? (2)
1. Suicidal thoughts and behaviour
2. Switching between brands
In category 3
92
Common side effects of Levetiractam? (5 groups)
1. Anxiety, Depression, Mood altered, Insomnia
2. GI discomfort, nausea, diarrhoea, vomiting, cough
3. Dizziness, drowsiness, movement disorders, vertigo
4. Appetite decreased , asthenia (lack of energy)
5. Increased risk of infection, skin reactions
93
Uncommon side effects of Levetiractam? (3 groups)
1. Alopecia, weight changes, conc impaired
2. Leukopenia, muscle weakness, myalgia (muscle pain), thrombocytopenia
3. Hallucination, confusion, paraesthesia (pins and needles)
94
Rare side effects of Levetiractam? (4 groups)
1. AKI, hepatic disorder, pancreatitis
2. Agranulocytosis, neutropenia
3. Hyponatreamia
4. Severe cutaneous adverse reactions (SCARs)
95
```
Advice for levetiracetam in
pregnancy:
breastfeeding:
hepatic impairment:
renal impairment:
```
1. Pregnancy: dose monitored/adjusted, fetal growth monitored
2. present in breast milk - avoid
3. caution in severe hepatic impairment - reduce 50% if creatinine clearance less than 60ml/min/1.73m2
4. reduce in children with eGFR less than 80ml/min/1.73m2
In adults
max 2g daily - eGFR 50-80
max 1.5g daily if eGFR 30-50
max 1g daily if eGFR less than 30
96
Directions of administration for Levetiractam (Keppra)
IV?
Oral ?
IV - dilute with at least 100ml 5% glucose or 0.9% sodium chloride
Oral - can me diluted in a glass of water
97
Indications for sodium valproate?
1. All forms of epilepsy
| 2. Migraine prophylaxis (not licensed)
98
Some brand names of Sodium valproate? (4)
1. Epival
2. Episenta
3. Epilim Chrono
4. Epilim Chronosphere
99
MHRA advice for Sodium Valproate? (3)
1. Suicidal thoughts
2. Changing brands - category 2 consult Dr first
3. Contraindicated in women/girls unless conditions of pregnancy prevention programme are met.
Sodium valproate must be dispensed in whole packs. those dispensed to women/girls childbearing age should have a warning label on carton or sticker. Must discuss risks each time it is dispensed.
100
What are the risks in women/girls of childbearing age with the use of sodium valproate?
High teratogenic -
neurodevelopmental disorders
congenital malformations
101
Contraindications for sodium valproate? (4)
1. Acute porphyrias
2. Known or suspected mitochondrial disorders (higher rate of acute liver failure and liver-related deaths)
3. Personal or family history of severe hepatic dysfunction
4. Urea cycle disorders (risk of hyperammonaemia)
102
Cautions with the use of sodium valproate?
1. Systemic lupus erythematosus
2. Vit D supplementation
3. Liver dysfunction - monitor liver function. Raised liver enzymes during treatment usually transient but if prolonged discontinue.
103
Common side effects of sodium valproate?
What are the specific side effects?
1. GI - nausea, diarrhoea, abdo pain, vomiting
2. Menstrual cycle irregularities, alopecia, anaemia
3. Hyponatraemia, haemorrhage, thrombocytopenia
4. Hallucination, confusion, concentration impaired
1. Hepatic dysfunction - withdraw treatment immediately if persistent vomiting, anorexia, abdo pain, oedema, jaundice loss of seizure control.
2. Pancreatitis - discontinue if symptoms of pancreatitis develop - similar symptoms of above
104
Can sodium valproate be used in pregnancy for migraine prophylaxis or bipolar disorder?
No
105
If valproate is to be used during pregnancy - how should it be used?
Lowest effective dose in divided doses or as modified-release tablets to avoid peaks in plasma-valproate concentrations.
Doses greater than 1 g daily are associated with an increased risk of teratogenicity.
106
Can sodium valproate be used in
breastfeeding
hepatic
renal?
Breastfeeding - present in milk - risk of haematological disorders
hepatic - avoid
renal - reduce dose
107
Monitoring for sodium valproate?
What effect can SV have on lab tests?
1. Liver function test before therapy and during first 6 months
2. FBC
3. False +ve urine tests for ketones
108
How can Sodium valproate be taken?
Epival Tablets - can be crushed /chewed?
Epilim Syrup? how long can be used?
Episenta capsules?
Episenta / Epilim granules?
Tablets can be halved...NOT chewed or crushed
Syrup - can be diluted ideally in Syrup BP. Use within 14 days
Caps/ Granules - can be mixed with soft food or drink that is cold or at room temp and be swallowed without chewing
109
What are the requirements of the Pregnancy prevention programme?
1. Highly effective contraceptive in all women of childbearing potential e.g. intrauterine device or progesterone implant or two complementary forms of contraception inc. a barrier method should be used.
If not highly effective for e.g. condoms, diaphragm, oral contraceptive. Need to be used with a barrier + pill + frequent pregnancy testing
2. Updated & signed Annual Risk Assessment form each time a repeat Rx is issued
3. Referred for annual review
pharmacist needs to give patient card
110
Caution with the use of topiramate in strenuous activity or warm environment. What is there a risk of?
risk of nephrolithiasis—ensure adequate hydration
111
Topiramate shares similar side effect profile to to other anti-epileptics - what are some extra & which is one in particular it is associated with?
**with acute myopia with secondary angle-closure glaucoma, typically occurring within 1 month of starting treatment
If raised intra-ocular pressure occurs: seek specialist ophthalmological advice; use appropriate measures to reduce intra-ocular pressure and stop topiramate as rapidly as feasible.
eye discomfort/disorder, dry eye, glaucoma
ear discomfort
Hypokalaemia
112
Risk in pregnancy with topiramate use?
Increased risk of major congenital malformations following exposure during the first trimester.
if taken during first trimester - careful prenatal monitoring should be performed.
It is recommended that the fetal growth should be monitored.
For migraine prophylaxis manufacturer advises avoid.
For epilepsy manufacturer advises consider alternative treatment options.
113
Topiramate in
breastfeeding:
hepatic
renal?
breastfeeding - avoid
hepatic - with caution as risk of decreased clearance
renal - in adults & children half usual starting and maintenance dose if eGFR less than 70. due to reduced clearance and longer time to steady state plasma concentration.
114
Indication for Phenobarbital?
All forms of epilepsy except typical absence seizures
Status epilepticus
115
Are phenobarbital and phenobarbital sodium equivalent in effect?
Yes
116
What are the specific side effects of phenobarbital?
Oral
Parenteral use?
Oral use:
Anxiety, Hallucination
Megaloblastic anaemia
Severe cutaneous adverse reactions (SCARs), thrombocytopenia
Parenteral use:
Agitation, anaemia, toxic epidermal necrolysis, hypocalcaemia, Dupuytren's contracture (hand deformity - where fingers pulled into bent position)
117
Plasma concentration for phenobarbital? Is it a useful measure?
optimum response is 15–40 mg/litre (60–180 micromol/litre); however, monitoring the plasma-drug concentration is less useful than with other drugs because tolerance occurs.
118
Can phenobarbital tablets be crushed if taken orally?
When a liquid special is required for children what should it be & strength?
Yes can be crushed
should be alcohol free and 50mg/5ml strength
119
Phenobarbital overdose can be treated with?
Which other drug overdoses can this substance be used for?
Activate charcoal
1. Carbamazepine
2. Dapsone ( sulphonamide antibiotic)
3. Quinine (for malaria)
4. Theophylline
120
Phenobarbital overdose can be treated with?
Which other drug overdoses can this substance be used for?
What if it is serious overdose of pheno in hospital?
Activate charcoal
1. Carbamazepine
2. Dapsone ( sulphonamide antibiotic)
3. Quinine (for malaria)
4. Theophylline
can use haemodialysis
