Chapter 4 - Central Nervous System Flashcards
What are the most effective contraceptive measures whilst on Valproate?
User independent methods such as:
- The long acting reversible contraceptives (LARC)
- Copper intrauterine device (Cu-IUD)
- Levonorgestrel intrauterine system (LNG-IUS)
- Progestogen only implant (IMP)
- Female sterilisation
All have a failure rate of less than 1% with typical use.
User dependent methods such as the condom, cap, diaphragm, combined oral contraceptive pill (COC) or progestogen-only contraceptive pill (POP) and fertility awareness based methods are not considered highly effective since the typical use incorporates user failure risks
What are the risks of taking Valproate during pregnancy?
It can seriously harm your unborn baby in two ways:
• Birth defects when the baby is born
• Problems with development and learning as the child grows up.
What type of birth defects can Valproate cause?
Spina bifida - where the bones of the spine do not develop properly.
Face and skull malformations – including ‘cleft lip’ and ‘cleft palate’. This is where the upper lip or bones in the face are split.
Malformations of the limbs, heart, kidney, urinary tract and sexual organs.
Neural tube defects
Facial dysmorphism,
Craniostenosis
Will taking Folic acid whilst on Valproate help reduce the risk of birth defects?
It’s unlikely
What child developmental problems are known to be associated with Valproate use in pregnancy?
- Being late in learning to walk and talk.
- Lower intelligence than other children of the sameage.
- Poor speech and language skills.
- Memory problems.
more likely to have autism or autism spectrum disorders.
may be more likely to have signs of Attention Deficit Hyperactivity Disorder (ADHD).
Valproate use in those too young to become pregnant?
Only used if nothing else works.
Contact GP or specialist as soon as your periods start during valproate use to have your treatment reviewed
What should a woman do if she decides to plan to become pregnant whilst on Valproate?
Talk to her doctor as soon as possible
Do not stop taking valproate or using contraception until you have spoken with your doctor.
Once spoken to the doctor:
Ensure she understands the risks of valproate in pregnancy
Switch valproate to another therapeutic option
Tell her not to stop contraception until the switch is achieved and she is no longer taking valproate
If switching is not possible refer for counselling about the risks.
Valproate indication
Epilepsy and bipolar disorder
Unplanned pregnancy whilst on Valproate
- There is no dose threshold considered to be without any risk. However, the risk of birth defects and developmental disorders is higher at greater doses (above 1g daily)
- Use the lowest effective dose and divide the daily dose of valproate into several small doses to be taken throughout the day
- The use of a prolonged release formulation may be preferable to other treatment formulations in order to avoid high peak plasma concentrations
- All patients with a valproate exposed pregnancy and their partners should be referred to a specialist experienced in prenatal medicine.
Role of Pharmacist when presented with a patient of child bearing potential on Valproate
- Ensure the Patient Card is provided every time valproate is dispensed
- Remind patients of the risks in pregnancy and the need for highly effective contraception
- Remind patients of the need for annual specialist review
- Ensure the patient has received the Patient Guide
- Dispense valproate in the original package. In situations where repackaging cannot be avoided always provide a copy of the package leaflet and add a sticker with the warning to the outer box
- If a woman of childbearing potential reports that she is not taking highly effective contraception, refer them to their GP (including by contacting the GP if necessary).
How is Valproate withdrawn?
Gradually over weeks to months, which allows an
opportunity to identify the likely minimum required dose should a seizure occur during drug withdrawal.”
How is Valproate changed to another medication and how long does it take?
The switch of valproate to an alternative treatment will commonly occur over at least 2–3 months.
The new medication is usually first gradually introduced as add on to valproate. This can take up to 6 weeks to reach a potentially effective dose of the new treatment; thereafter an attempt can be made to gradually withdraw valproate.
Pregnancy Prevention Programme for Valproate ensures
All female patients taking valproate medicines:
- have been told and understand the risks of use in pregnancy and have signed a Risk Acknowledgement Form
- are on highly effective contraception if necessary
- see their specialist at least every year
Warnings added to the packaging of valproate medicines
A visual warning symbol will be added to the carton of valproate medicines by September 2018. This symbol will show a pregnant woman in a red circle with a line through it, with warning text about the risks and information about the new measures.
