Sodium Valproate Flashcards
What are the indications for sodium valproate?
All forms of epilepsy
migraine prophylaxis
Mania
What is sodium valproate contraindicated in?
Acute porphyria, known or suspected mitochondrial disorders, Hepatic dysfunction, urea cycle disorders
What are the signs of toxicity?
perisistent vomiting, abdo pain, anorexia
Jaundice, oedema, drowsiness
Loss of seizure control
Suicidal ideation
What are the monitoring requirements of sodium valproate
LFT before and within 6 months if at high risk
FBC before starting and before surgery
Weight
BMI
Pregnancy test
What are the important actions of sodium valproate
- Pregnancy prevention programme
- Need a negative pregnancy test to initiate therapy
- Need a user independent form of contraception e.g. IUD or Implant or 2 complimentary forms AND barrier method
- patients immobilised or have inadequate sun exposure or dietary intake of calcium then should take a vitamin supplementation
- reduce gradually over atleast 4 weeks if want to stop
What are the interactions of sodium valproate?
- effects of antipsychotics, MOAI, antidepressants and benzodiazepines are potentiated
- Anticoagulant effect of warfarin increased
- Metabolism of Lamotrigine reduced, half life doubled which leads to toxicity - steven johnson syndrome
- Erythromycin and cimetidine may increase valproic acid plasma levels
- Anti-epileptics with enzyme inducing effect decrease valproic levels
What effect does valproate have on the CYP substrates?
Enzyme inhibitor
What are the non-specific side effects of sodium valproate?
Depression and suicide
Hepatotoxicity
Hypersensitivity
Blood dycrasias
Vitamin D deficiency –> bone pain
What are the specific side effects of sodium valproate?
Pancreatitis
Teratogenicity
What are the risks in males?
Impaired fertility
Under the new guidance, at what age are patients not allowed to be prescribed valproate unless two specialists have decided that all other treatments are not suitable?
Under 55’s
