Anticonvulsants

Question 2

prolonged seizure treatment algorithim

Answer 2

1. Benzodiazepine dose 1
2. If still fitting after 10 mins, benzodiazepine dose 2
3. Phenytoin or levetiracetam (keppra)
4. If beyond 30 mins - Refractory status epilepticus (RSE) is defined as status epilepticus that continues despite treatment with benzodiazepines and one antiepileptic drug. - rapid sequence endotracheal intubation and mechanical ventilation - thiopentone in fitting pt (has anti-seizure properties)

Question 3

what benzodiazepine should you use in prolonged seizure algorithim in diff settings?

Answer 3

Pre-hospital buccal midazolam 10mg may be given by carers etc

Hospital setting w/o IV access - give rectal diazepam 10mg

Hospital setting w IV access - give 4mg IV lorazepam

Question 4

benzodiazepine SE/risks

Answer 4

CNS depressive affects
resp depression

Question 5

antidote benzodiazepines? works well for?

Answer 5

Flumazenil is antidote (selective competitive antagonist of the gamma-aminobutyric acid (GABA) receptor)

• Flumazenil may be effective in reversing the sedation that occurs in a benzodiazepine overdose, but its effects on reversal of depressed breathing is less predictable.

Question 6

Phenytoin considerations and dosing

Answer 6

20mg/kg loading dose
then 100mg every 6-8 hrs

DO NOT GIVE LOADING DOSE IF ALREADY ON PHENYTOIN - THEORETICAL RISK

It is Contraindicated in:
Second- and third-degree heart block; sino-atrial block; sinus bradycardia; Stokes-Adams syndrome, pregnancy
Ask if pregnant
Ask about medications and risk of CA
ECG monitor

Question 7

What alternative drugs could you use if phenytoin is contraindicated?

Answer 7

Sodium valproate
Phenobarbital

Question 8

When do you start treatment for epilepsy

Answer 8

Most neurologists now start antiepileptics following a second epileptic seizure.

unless:
the patient has a neurological deficit
brain imaging shows a structural abnormality
the EEG shows unequivocal epileptic activity
the patient or their family or carers consider the risk of having a further seizure unacceptable

Question 9

what to consdier when choosing anti-epleptic

Answer 9

• other medications antiepileptics can induce/inhibit the P450 system resulting in varied metabolism of other medications, for example warfarin
• contraception both the effect of the contraceptive on the effectiveness of the anti-epileptic medication and the effect of the anti-epileptic on the effectiveness of the contraceptive need to be considered
• pregnancy or wanting to get pregnant
• breastfeeding

Question 10

Management generalised tonic-clonic seizures

Answer 10

men, girls under 10 unlikely to need in future, women unable to have children
1. sodium valproate

women and girls
1. lamotrigine or levetiracetam

Question 11

Management focal seizures

Answer 11

1. lamotrigine or levetiracetam
2. carbamazepine, oxocarbazepine, zonisamide
3. lacosamide

Question 12

management absence seizures

Answer 12

1. ethosuximide
2. sodium valproate

sodium valproate particularly effective if co-existent tonic-clonic seizures in primary generalised epilepsy

Question 13

management myoclonic seizures

Answer 13

boys and men, girls under 10 unlikley need in future, women unable to have children
1. sodium valproate

women and girls
1. levetiracetam

Question 14

management tonic/atonic seizures

Answer 14

boys and men, girls under 10 unlikley need in future, women unable to have children
1. sodium valproate

women and girls
1. lamotrigine

Question 15

what seizures may carbamazepine exacerbate

Answer 15

absence and myoclonic

Question 16

risk benefit epilepsy management in pregnancy

Answer 16

The risks of uncontrolled epilepsy during pregnancy generally outweigh the risks of medication to the fetus.

All women thinking about becoming pregnant should be advised to take folic acid 5mg per day well before pregnancy to minimise the risk of neural tube defects. Around 1-2% of newborns born to non-epileptic mothers have congenital defects. This rises to 3-4% if the mother takes antiepileptic medication.

Question 17

management of epilepsy in pregnancy

Answer 17

folic acid 5mg per day well before pregnancy

monotherpay - lamotrigine

Question 18

sodium valproate pregnancy associations

Answer 18

associated with neural tube defects

most common defect - hypospadias

significant risk of neurodevelopmental delay in children following maternal use of sodium valproate.

Question 19

phenytoin pregnancy associations

Answer 19

cleft palate

Question 20

breastfeeding anti-epileptics

Answer 20

Breast feeding is generally considered safe for mothers taking antiepileptics with the possible exception of the barbiturates