EPILEPSY DRUGS/ ASMS

learning disability / intellectual ability definition

the presence of a significantly reduced ability to understand new or complex information or learn new skills with a reduced ability to cope independently

Enzyme inducer anti-seizure medications

Carbamazepine

phenytoin

topiramate

Enzyme Inhibitor anti-seizure medication

sodium valproate

anti-seizure medication which are enzyme inducers and reduce the effectiveness of oestrogen and progestogen

Carbamazepine

phenytoin

topiramate

→ increased risk of pregnancy

Least appropriate anti-seizure medications for Combined Oral contraceptive or Progesterone only pills

Carbamazepine

phenytoin

topiramate

Lamotrigine (POP)

→ increased risk of pregnancy

oestrogen effect (combined oral contraceptives) on lamotrigene

Reduces the effect of lamotrigene → uncontrolled seizures / loss of seizure control

lamotrigine not recommended for progestogen only pills

decreases the effect causing loss of pill control → increased risk of pregnancy

antiseizure medications which acts on sodium channels

carbamazepine

Lamotrigene

advice for avoiding / reducing side effects of carbamazepine

• titrate slowly

• use Modified-release formulation

• Take with food

anti-seizure medication most likely to make seizures worse and be poorly tolerated

carbamazepine

the worst anti-seizure medication for a pregnant woman due to teratogenic effects

Valproate

anti-seizure medications which cause vitamin D deficiency / effect vitamin D metabolism

• carbamazapine

• valproate

moderately safe in pregnancy but still cause physical malformation

1. lamotrigene

2. levetiracetam

side effects of carbamazapine

• can make some seizures worse

• not well tolerated - nausea , vomiting

• causes vitamin D deficiency

issue with giving lamotrigene during pregnancy

the concentration is significantly and unpredictably altered in pregnancy

Need to reduce mothers dose at birth which can be difficult

anti-seizure medication least appropriate for myoclonic seizures

lamotrigine - makes them worse

Side effect of lamotrigene

hypersensitivity reactions like rashes (10% of ppl experience)

can cause SJS

anti-seizure medication least likely to interact with other drugs

levetiracetam

anti-seizure medication least appropriate to use for seizures in a patient with psychotic/behavioural disorders like bipolar or schizophrenia

levetiracetam

side effects of levetiracetam

• causes increased energy and concentration

• causes psychotic and behavioural adverse effects

• causes aggression

anti-seizure medication least appropriate for someone on a diet/ obese/ BMI of 30/ has diabetes due to weight gain ADR

Valproate

side effects of valproate

1. weight gain

2. vitamin D deficiency

3. teratogenic when taken during pregnancy - hearing, deafness & developmental disorders

key concepts of the MHRA pregnancy prevention programme

1. for women of child bearing potential who are on valproate

2. they must go through an annual review with a specialist to fill out the Annual Risk Acknowledgement Form

3. these women need to be on a contraception to prevent pregnancy

contraceptives for women taking Valproate or Topiramate

1. Copper Intrauterine Device (Cu-IUD)

2. Mirena IUS coil

3. Progestogen implant (only if on valproate only)

4. female sterilisation

5. combined oral contraceptive + condom/spermicide

contraceptives for women taking Carb,Phen,Top / lamotrigene

1. Depo-provera injection

2. Copper Intrauterine device

3. Intrauterine system - Mirena Coil

Only combined oral contraceptive that can be given for a woman on Carb,Phen,Top

High dose / 5mcg Oestrogen with a 4 day free period

contraceptives which may be used for women taking lamotrigene for epilepsy seizures

1. depo-provera injection

2. copper intrauterinene device

3. Mirena IUS Coil

Advice for women with epilepsy planning to get pregnant

1. Take oral folic acid 5mg daily for at least 12 weeks of pregnancy

Advice for women with epilepsy after giving birth

1. breast feeding is good, best to do it before the next ASM dose

2. monitor any ADRs in child

Oestrogen in relation to the menstrual cycle has what effect on GABA (periods are a trigger of epilepsy)

inhibits GABA (triggers seizures)

Adverse effect of depo-provera injection

osteoporosis → speeds up bone loss

Use of depo-provera cautioned in

• under 18s

• over 45s

recommended diet for epileptic children

ketogenic diet

Duration in which people cannot drive when their ASM is being withdrawn

up to 6 months after withdrawal

Inhibits gaba and increases likelihood of seizures

Oestrogen