anti epileptic drugs Flashcards
1
Q
sodium valporate
A
- increases GABA activity
2. first line for generalised seziures
2
Q
Carbamazepine
A
- binds to sodium channels increasing their refractory period
- first line for partial seizures
3
Q
Lamotrigine
A
- sodium channel blocker
2. used second line for a variety of partial and generalised seizures
4
Q
phenytoin
A
- binds to sodium channels increasing their refractory periods
- no longer used first line due to side effect profile
5
Q
Groups of patients to consider when prescribing anti epileptics
A
- patients who drive:
- generally patients cannot drive for 6 months following a seizure.
- For patients with established epilepsy they must be fit free for 12 months before being able to drive - patients taking other medications: antiepileptics can induce/inhibit the P450 system resulting in varied metabolism of other medications, for example warfarin
- women wishing to get pregnant:
- antiepileptics are generally teratogenic, particularly sodium valproate.
- It is important that women take advice from a neurologist prior to becoming pregnant, to ensure they are on the most suitable antiepileptic medication.
- Breast feeding is generally considered safe for mothers taking antiepileptics with the possible exception of the barbiturates - women taking 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
6
Q
Carbamazepine is used for;
A
- partial seizures
2, neuropathic pain (e.g. trigeminal neuralgia, diabetic neuropathy)
- bipolar disorder
7
Q
Adverse effects of Carbamazepine
A
- P450 enzyme inducer
- dizziness/drowsiness/headache
- visual disturbance
- leucopenia and agranulocytosis
- may exacerbate myoclonic/absence seizures
8
Q
adverse effects of Phenytoin
( chronic)
A
- gingival hyperplasia - enlarged size of the gums, secondary to increased expression to platelet derived growth factor
- Hirsutism
- megaloblastic anaemia - secondary to altered folate metabolism
- enhanced vitamin D metabolism causing osteomalacia
9
Q
adverse effects of Phenytoin
( teratogenic )
A
- assoc with cleft palate and congenital heart disease
10
Q
adverse effects of Phenytoin
( idiosyncratic )
A
- Fever
- rashes, including severe reactions such as toxic epidermal necrolysis
- hepatitis
- Dupuytren’s contracture*
- aplastic anaemia
- drug-induced lupus