Sodium valproate, pregabalin, Gabapentin & ADHD Flashcards
What is Sodium Valproate for?
For all forms of epilepsy, mania & migraine prevention (unlicensed)
Can Sodium Valproate be used in pregnancy and women of child bearing age?
Cannot be used in pregnancy because it is highly teratogenic and leads to neuro defects and congenital malformations.
Avoid in women of child bearing age unless conditions of PPP are met
What are the side effects of Sodium Valproate?
- Liver toxicity (esp in children under 3)
- Blood and hepatic disorders
- Pancreatitis can occur (N&V, abdominal pain) - discontinue if occurs
- Can effect clotting - discontinue if prolonged prothrombin time
What MHRA warnings are used with Sodium Valproate?
- Risk of suicidal thoughts & behaviours (this happens with all antiepileptics)
- There can be a spontaneous adverse reaction when switching patients previously stabilised on branded products to generic
- Should be avoided in pregnant women and those of child bearing age unless conditions of PPP are met
- Consider Vitamin D supplementation in patients that are immobilised for long periods of time or who have inadequate sun exposure or dietary intake of calcium.
This is because sodium valproate reduces bone density and correcting vitamin D deficiency reduces risk of seizures
Which antiepileptics are safe to use in pregnancy?
- Lamotrigine
- Levetiracetam
What is the best method of contraception for women on valproate?
Some form of IUD like Cu-IUD = copper intrauterine device
What is the caution of Valproate?
Liver toxicity - Assess patients with raised liver enzymes and monitor them.
What are the side effects of Valproate?
- Appetite increase (weight gain)
- Liver failure
- Pancreatitis - P-450 inhibitor.
- Reversible hair loss
- Oedema
- Ataxia
- Teratogenicity
- Tremor
- Encephalopathy
What are the serious valproate interactions?
Lamotrigine = Valproate increases the exposure to lamotrigine. So adjust dose of lamotrigine and monitor rash. Lamotrigine can also cause SJS - risk higher in Han Chinese & Thai ethnicities.
Olanzapine = Increases risk of adverse effects
Phenytoin = Valproate affects the concentration of phenytoin and phenytoin decreases the concentration of valproate. So monitor concentration.
Topiramate = Topiramate increases the risk of toxicity when given with valproate. So monitor
Pivmecillinam = Avoid, increases risk of adverse effects
Ertapenem, Imipenem, meropenem - COMPLETELY AVOID. It decreases of valproate.
What patient and carer advice must be given with Valproate?
Recognise signs of blood, hepatic disorders and pancreatitis.
Women and girls should NOT stop taking valproate without first discussing it with their doctor.
And ensure female patients have a patient card and all safety info.
What is Vigabatrin used for?
Focal seizures
Can Vigabatrin be used for absence, myoclonic, tonic and atonic seizures?
No, it worsens it.
What’s a side effect of Vigabatrin?
Visual disturbances.
Visual defects continue even after stopping the drug.
Report any visual symptoms urgently
When should monitoring for Vigabatrin be done?
Test before treatment and at 6 month intervals
What are Gabapentin & Pregabalin used for?
To treat focal seizures.
And they are licensed for neuropathic pain
Pregabalin - licensed for treatment of generalised anxiety disorder.
