Sodium valproate is used in epilepsy and in bipolar disorder. It is effective, and it carries one risk serious enough that it shapes how the medicine is prescribed to anyone who could become pregnant.
Taken during pregnancy, sodium valproate can cause serious birth defects and long-term developmental and learning problems in the child. Because of this it is not prescribed to girls or women who could become pregnant unless there is no suitable alternative and specific pregnancy-prevention conditions are met, including reliable contraception and regular specialist review.
If this applies to you, make sure you have had that conversation, understand the requirements, and know who to contact. Do not stop the medicine on reading this. Stopping abruptly can cause seizures or relapse. Contact your specialist urgently instead, and if you are pregnant or think you might be, contact them the same day.
Common side effects and early adjustment effects
- Nausea and stomach upset, often easing and often reduced by taking it with food
- Drowsiness
- Tremor, typically of the hands
- Weight gain and increased appetite
- Hair thinning, sometimes with a change in texture when it regrows
- Dizziness or unsteadiness
Weight gain and tremor are both common enough to be worth raising early, since dose adjustment sometimes helps.
Serious mood, behaviour or physical symptoms to take seriously
Liver problems. Get urgent help for persistent vomiting, marked loss of appetite, unusual tiredness or weakness, abdominal pain, yellowing of the eyes or skin, or a sudden return of seizures. Liver injury is uncommon but most likely in the first six months, and the risk is highest in very young children.
Pancreatitis. Severe, persistent abdominal pain with vomiting needs urgent assessment.
Raised ammonia. Unexplained drowsiness, confusion, or a change in alertness can indicate this and needs a blood test rather than waiting.
Blood effects. Report unexplained bruising or bleeding, or frequent infections.
Also seek urgent help for a rash that blisters or peels, and for new or worsening thoughts of self-harm.
Sexual, sleep, weight and emotional side effects
Weight gain is one of the more common reasons people find valproate difficult, and it is easier to address early than after it accumulates. See mental health medication and weight gain.
Drowsiness affects daytime function and driving. Hair thinning is usually reversible and worth mentioning.
Menstrual changes and polycystic ovary syndrome have been associated with valproate and should be reported.
Interactions, alcohol, pregnancy and other risk factors
- Lamotrigine. Valproate substantially raises lamotrigine levels, requiring a much lower lamotrigine dose. See lamotrigine side effects.
- Other epilepsy medicines. Several interact in both directions.
- Aspirin and anti-inflammatories. Can raise valproate levels and add bleeding risk.
- Alcohol. Adds liver strain and drowsiness.
- Supplements. Check before starting anything new. See supplement and medicine interactions.
Monitoring usually includes liver function and full blood count, particularly in the first months, along with weight.
What to ask your doctor before changing dose or stopping
Never stop this medicine abruptly. If it is being taken for epilepsy, sudden withdrawal can trigger seizures, including prolonged seizures that are themselves dangerous. If it is being taken for mood stabilisation, stopping suddenly carries a high risk of relapse. Any reduction is planned with your prescriber.
- Given the pregnancy risk, is this still the right medicine for me?
- What contraception and review arrangements do I need to be on this?
- When are my liver tests and blood counts due?
- Which symptoms should make me contact you the same day?
- Who do I contact urgently if I become pregnant?
Related mental health medication guides
- Mood stabiliser side effects
- Epilepsy medication side effects
- Bipolar medication side effects
- Should I stop my mental health medication
- Report a side effect in South Africa
See also valproate side effects and Epilim, a South African valproate brand.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.