Epilepsy and mental health
Epilepsy is a common neurological disorder affecting around 600,000 people in the UK. There are many types of epilepsies and all are characterised by the occurrence of recurrent seizures. Epilepsy is usually of short duration and it only becomes a chronic condition in around 20% of patients. An epilepsy diagnosis is sometimes difficult to make and it needs to be confirmed by a neurologist. It can sometimes be confused with: vasovagal syncope, cardiac syncope, panic attacks, schizophrenia or “pseudo-seizures”.
Correlations with epilepsy and mental health
Psychiatric comorbidities are common in epilepsy and they sometimes go undiagnosed and untreated. Around one in three patients with epilepsy will develop depression, anxiety is common, and suicide rates are three times higher in epileptic patients than in the general population. Memory difficulties, reduced concentration and fatigue have also been associated with epilepsy. Moreover, there is a prevalence of 4% for the comorbidity of psychosis with epilepsy.
Epilepsy is more prevalent in people with learning disabilities and seizures may be more complex, prolonged and frequent than in the general population. It can be difficult to distinguish between certain behaviours, like automatisms or confusions, and a seizure for people with learning difficulty.
What antiepileptic drugs are available?
There is a wide range of antiepileptic drugs (AEDs) available in the UK. Most come with some troublesome side effects and treatment is usually long-term. When starting an AED, patient characteristics, epilepsy syndrome, lifestyle and prognosis should be considered. AEDs normally require a slow titration at the start to reduce side effects and find the lowest effective dose.
Great care is needed when changing between AEDs, and the MHRA advises avoiding routine changes. It also recommends using the same brand or manufacturer for AEDs, otherwise, there is increased risk for lowering the seizure threshold, in particular for carbamazepine, phenytoin, phenobarbital and primidone.
Carbamazepine is indicated for generalised tonic-clonic and partial seizures and the slow release preparation should ideally be used. Carbamazepine is a potent enzyme inducer and it may reduce plasma levels of some other drugs.
Sodium valproate is indicated for all forms of epilepsy but it should ideally not be used in female children or females of childbearing potential due to its teratogenic effect.
Lamotrigine is licensed for all forms of epilepsy (as monotherapy or an adjunctive) and it appears to be more effective than carbamazepine because it is better tolerated, has a favourable cognitive and behavioural profile and it does not lead to weight gain. It’s key to start lamotrigine slowly (25-50mg daily, 50-100mg increases 7-14 days after) as it has been related to serious skin disorders.
Complications of epilepsy and mental health
Certain psychotropic drugs have been related to seizures. Examples include all antipsychotics (clozapine and chlorpromazine are considered “high-risk”), antidepressants (SSRI are considered “safer” than tricyclics), buspirone, lithium, anticholinesterases, atomoxetine and St John’s Wort.
Any seizure lasting longer than five minutes should be treated as a medical emergency because prolonged seizures may damage the brain and cause death. In secondary care/community, the two main drugs used to treat long-lasting seizures are buccal midazolam (only licensed in children under 18) and rectal diazepam. General supportive measures, like protecting the patient from injury, cushioning their head, timing the seizure, placing the patient in the recovery position, checking/opening the patient’s airway and being calm and reassuring, should be followed when dealing with a seizure.
New Ashtons training seminar on epilepsy and mental health
Ashtons is now offering a new clinical seminar in this field called “Epilepsy and Mental Health” which may help to develop your team knowledge and skills. Please contact your Ashtons visiting pharmacist for more information.
- SIGN: “Diagnosis and management of epilepsy in adults” (2015) http://www.sign.ac.uk/assets/sign143.pdf
- NICE: “Epilepsies: diagnosis and management” (2012) https://www.nice.org.uk/guidance/cg137/chapter/1-Guidance
- British National Formulary (73 Edition) (2017)
- Medicines compendium: https://www.medicines.org.uk/emc/
- The Maudsley: “Prescribing Guidelines in Psychiatry” (12th Edition)
- “The Psychotropic Drug Directory” (2016)
- “Shorter Oxford Textbook of Psychiatry” (6th Edition)
- Royal College of Psychiatry: “Prescribing anti-epileptic drugs for people with epilepsy and intellectual disability [CR 206]” http://www.rcpsych.ac.uk/files/pdfversion/CR206.pdf