Anti-epileptics Flashcards
Valproate - indications ?
- epilepsy - first line for prophylaxis of tonic clonic seizures, absence, focal and myoclonic
- some Status epilepticus - those not responding to benzos
- Bipolar - acute treatment of manic and prophylaxis against recurrence
valproate - MOA?
Weakly inhibits neuronal sodium channels, stabilising resting membrane potentials and reducing neuron excitation.
+ increases GABA
valproate SE
GI upset
neuro and psych: ataxia, tremor and behaviour change
thrombocytiopenia
deranged lfts
hair loss
BMF, Pancreatitis, antiepileptic hypersensitivity syndrome
Teratogenic
Valproate warnings
not for women of child bearing age esp not in 1st trimester
avoid in hepatic impairment and reduce dose in severe renal impairment
valproate interactions
- inhibits cyp450
- increases plasma conc of lamotrigine and cyp450 drugs e.g. warfarin
valproate starting dose for epilepsy
600mg
valproate starting dose for bipolar
750mg 1-3 divided doses . maintain at 1-2g
what advice can you give to patients on valproate to avoid upset tummy
take with food
DVLA advice on valproate
Advise patients not to drive unless they have been seizure-free for 12 months, and for 6 months after changing or stopping treatment.
Carbemazepine indications
- epilepsy - prophylaxis for tonic clonic and focal
2. trigeminal neuralgia
MOA of carbemazapine
inhibit neuronal sodium channels -
SE of Carbemazapine
Gi upset
neurological effects - ataxia and dizzy
odoema
hyponatraemia
hypersensitvity - rash
antiepileptic hypersensitivity syndrome - 2 months of treatment - SJS and pyrexia
what are the teratogenic effects of carbamezapine
neural tube defects, cardiac and urinary tract problems and cleft palate
if must take during pregnancy - high dose folic acid.
what situations should you prescribe carbamezapine with caution
hepatic, renal or cardiac disease
important interactions of carbemazapine
cyp 450 inducer. do not give with cyp450 inhibiters e.g. macrolides
what two routes can you prescribe carbamezapine
PO
PR
how should you stop carbamezapine
taper slowly
gabapentin and pregabalin indications
- add on for focal epilepsies if others have failed
- neuropathic pain including painful diabetic neuropathy
- an option for generalised anxiety disorder