Adult Epilepsy Services in Dorset

1. Adult Epilepsy Services in Dorset Michelle Knight and Aideen Tarpey Epilepsy Specialist Nurses – Dorset Epilepsy Service

2. Epilepsy - in general • ‘Epilepsy’ is not a diagnosis per se but a symptom • Annual incidence of around 50 cases per 100,000 • Most common serious neurological condition • 40 types of seizures • Higher prevalence in young and elderly • Increased mortality & morbidity: • Standardised mortality ratio 2-4 times matched background: • Risk of death 23 times higher if uncontrolled seizures • Increased unemployment and dependency • Significant adverse side-effects associated with AEDs

3. SEIZURE TYPES • Seizures previously classed as “Grand Mal” or “Petit Mal” • These terms were considered too general as over 40 types of seizures • Reclassified in 1981 by ILAE

4. GENERALISED • Tonic – clonic • Tonic • Atonic • Absence • Myoclonic

5. PARTIAL • Simple – Partial • Complex – Partial • Secondary Generalised

6. Is treatment necessary? • Cumulative risk of single seizure 5% • Risk of 2nd seizure 50-80% within 3 years • 75% of these recur within 1 year • Focal & tonic-clonic seizures more likely • Syndromic diagnosis may provide more information • After 2-5 years of seizure freedom: • 60% seizure free (vs 80% of those still on AED)

7. Available anticonvulsants Acetazolamide (1952) Benzodiazepines (1950’s) Carbamazepine (1964) Ethosuximide (1958) Felbamate (USA – 1980’s) Gabapentin (1990’s) Lacosamide (2008) Lamotrigine (1990’s) Levetiracetam (2000) Oxcarbazepine (1980’s; UK 2000) Phenobarbital (1912) Phenytoin (1952) Piracetam (1967; myoclonus 1978) Rufinamide (2008) Stiripentol (2007) Tiagabine (1990’s) Topiramate (1990’s) Valproate (late 1960’s) Vigabatrin (1990’s) Zonisamide (Japan 1970’s)

8. Starting medication Choice of AED depends on individual factors Start low, go slow If not tolerated or not effective substitute alternative At least two trials of single agent at reasonable dose Little additional benefit for more than 2 agents

9. First Line Treatment • Carbamazepine • Lamotrigine • Sodium Valproate • Topirimate • Oxcarbazepine • Levetiracetam • Ethosuximide • Phenytoin

10. Acetazolamide Clobazam Clonazepam Gabapentin Lacosamide Phenobarbitone Phenytoin Piracetam Zonisimide Pregabalin Vigabatrin Tiagabine Stiripentol Rufinamide Primidone Topirimate Second line treatment

11. Levetiracetam (Keppra) • Monotherapy for partial onset seizures with or without secondary generalisation in patients from 16 years of age • Adjunctive therapy for partial onset seizures with or without secondary generalisation in adults and children from 4 years of age • Adjuctive therapy for myoclonic seizures in adults and adolescents from 12 years of age with JME • Adjunctive therapy for primary generalised tonic-clonic seizures in adults and adolescents from 12years of age with Idiopathic Generalised Epilepsy

12. The future…… • Once daily preparation of Sodium Valproate Chrono (Episenta) already being widely used • Zebinix – Once daily, evolved from Carbamazepine (but without many of the side effects) adjunctive therapy • More drugs in development……

13. Response to medication • Remission on single drug 60-80% • Dose required often relatively modest • Failure on first drug due to: • Adverse reaction - 48% • Lack of efficacy - 21% • 92% who go into remission do so in 3yrs • Compliance with medication may be a significant issue • Interactions with other medications

14. Rescue medication • Diazepam • Buccal midazolam (Epistatus) • Emergency care plan and training needed in administration, epilepsy awareness and first aid.

15. Generic vs. branded • “changing the formulation or brand of AED is not recommended because different preparations may vary in bioavailability or have different pharmacokinetic profiles and, thus, increased potential for reduced effect or excessive side effects.” NICE

16. Contraception • Enzyme inducing drugs (carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, topirimate and lamotrigine) reduce the effectiveness of hormonal contraception • Lamotrigine may make the COC less effective and the COC may reduce the amount of lamotrigine in the blood stream (HRT may also do the same) • Contraception not affected by AED’s include Barrier methods, Depro-Provera, IUD’s and IUS (mirena coil) • Morning after pill – if on enzyme inducing drug, need 3milligrams of levonorgestrel instead of 1.5 milligrams

17. Pregnancy • Women of childbearing age with epilepsy should take folic acid 5 milligrams a day. This should be continued throughout the pregnancy. (folic acid may interact with Phenytoin, phenobarbitone and primidone making them less effective) • Sodium valproate – PCOS risk may increase if taken from an early age • Pre-conceptual counselling – first three months of pregnancy, risk is greatest • Sudden stopping of medication not advised • Balance of risk of seizures / drug therapy • MCM – damaged spine, heart problems, cleft palate, hernia. Minor malformations

18. MCM’s • UK Epilepsy and Pregnancy register • General population risk is 1-2 babies in 100 will have MCM • Mothers who take AED’s, 4 in 100 will have MCM • Higher risk if more than 1 AED • Sodium Valproate is thought to carry highest risk (look at rationalising – Chrono) • Fetal anti-convulsant syndrome • Breast feeding • Seizures during pregnancy • Vitamin K 10-20mg during last month of pregnancy if on enzyme inducing drug • Pethadine not recommended • Management once baby is born

19. Osteoporosis and AED’s • Using AED’s long term can be a risk factor for bone loss and fractures • In particular, carbamazepine, phenobarbital, phenytoin, primidone and sodium valproate • Assess each patient and if necessary, refer for bone density scan

20. Thank you! Any Questions? Dorset Epilepsy Service – 01202 442231 / 01202 448486 dorset.epilepsy.service@poole.nhs.uk